Opacity

Download notebook View on GitHubRun when the site was built.

tikzfigure provides fine-grained control over transparency at every level: whole nodes, just the fill, just the stroke, paths, and the final PNG background. This tutorial covers:

opacity on nodes
fill_opacity vs draw_opacity independently
opacity and fill_opacity on paths
transparent vs white backgrounds with show() and savefig()
a practical Venn diagram

from tikzfigure import TikzFigure

`opacity` on nodes

opacity controls the overall transparency of a node (both fill and stroke together). A value of 1.0 is fully opaque; 0.0 is invisible.

The circles below overlap so you can see how lower opacity lets underlying content show through.

fig = TikzFigure()

opacities = [1.0, 0.8, 0.6, 0.4, 0.2]

for i, op in enumerate(opacities):
    fig.node(
        (i * 1.5, 0),
        shape="circle",
        fill="blue!60",
        draw="blue!80",
        minimum_size="2.5cm",
        opacity=op,
    )
    fig.node(
        (i * 1.5, -1.8),
        content=f"opacity={op}",
        draw="none",
        font=r"\tiny",
    )

fig.show()

/home/runner/work/tikzfigure/tikzfigure/.venv/lib/python3.12/site-packages/fitz/__init__.py:17: FutureWarning: The `fitz` API is deprecated and will be removed in future. Use `import pymupdf` instead.
  warnings.warn(

Show the TikZ code

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=1.0, minimum size=2.5cm] (node0) at ({0.0}, {0}) {};
    \node[draw=none, font=\tiny] (node1) at ({0.0}, {-1.8}) {opacity=1.0};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.8, minimum size=2.5cm] (node2) at ({1.5}, {0}) {};
    \node[draw=none, font=\tiny] (node3) at ({1.5}, {-1.8}) {opacity=0.8};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.6, minimum size=2.5cm] (node4) at ({3.0}, {0}) {};
    \node[draw=none, font=\tiny] (node5) at ({3.0}, {-1.8}) {opacity=0.6};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.4, minimum size=2.5cm] (node6) at ({4.5}, {0}) {};
    \node[draw=none, font=\tiny] (node7) at ({4.5}, {-1.8}) {opacity=0.4};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.2, minimum size=2.5cm] (node8) at ({6.0}, {0}) {};
    \node[draw=none, font=\tiny] (node9) at ({6.0}, {-1.8}) {opacity=0.2};
\end{tikzpicture}

Show the standalone LaTeX document

\documentclass[border=10pt]{standalone}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{groupplots}
\usetikzlibrary{arrows.meta}
\begin{document}
% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=1.0, minimum size=2.5cm] (node0) at ({0.0}, {0}) {};
    \node[draw=none, font=\tiny] (node1) at ({0.0}, {-1.8}) {opacity=1.0};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.8, minimum size=2.5cm] (node2) at ({1.5}, {0}) {};
    \node[draw=none, font=\tiny] (node3) at ({1.5}, {-1.8}) {opacity=0.8};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.6, minimum size=2.5cm] (node4) at ({3.0}, {0}) {};
    \node[draw=none, font=\tiny] (node5) at ({3.0}, {-1.8}) {opacity=0.6};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.4, minimum size=2.5cm] (node6) at ({4.5}, {0}) {};
    \node[draw=none, font=\tiny] (node7) at ({4.5}, {-1.8}) {opacity=0.4};
    \node[shape=circle, fill=blue!60, draw=blue!80, opacity=0.2, minimum size=2.5cm] (node8) at ({6.0}, {0}) {};
    \node[draw=none, font=\tiny] (node9) at ({6.0}, {-1.8}) {opacity=0.2};
\end{tikzpicture}

\end{document}

`fill_opacity` vs `draw_opacity`

fill_opacity and draw_opacity let you control the fill and stroke independently. Here every node has an opaque border but a translucent fill — a common styling choice for overlapping regions.

fig = TikzFigure()

colors = ["red", "blue", "green!60!black", "orange"]

for i, color in enumerate(colors):
    fig.node(
        (i * 2, 0),
        shape="circle",
        fill=color,
        draw=color,
        minimum_size="2cm",
        fill_opacity=0.3,
        draw_opacity=1.0,
        line_width=2,
    )

fig.show()

Show the TikZ code

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \node[shape=circle, fill=red, draw=red, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node0) at ({0}, {0}) {};
    \node[shape=circle, fill=blue, draw=blue, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node1) at ({2}, {0}) {};
    \node[shape=circle, fill=green!60!black, draw=green!60!black, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node2) at ({4}, {0}) {};
    \node[shape=circle, fill=orange, draw=orange, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node3) at ({6}, {0}) {};
\end{tikzpicture}

Show the standalone LaTeX document

\documentclass[border=10pt]{standalone}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{groupplots}
\usetikzlibrary{arrows.meta}
\begin{document}
% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \node[shape=circle, fill=red, draw=red, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node0) at ({0}, {0}) {};
    \node[shape=circle, fill=blue, draw=blue, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node1) at ({2}, {0}) {};
    \node[shape=circle, fill=green!60!black, draw=green!60!black, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node2) at ({4}, {0}) {};
    \node[shape=circle, fill=orange, draw=orange, fill opacity=0.3, draw opacity=1.0, minimum size=2cm, line width=2] (node3) at ({6}, {0}) {};
\end{tikzpicture}

\end{document}

`opacity` on paths

Paths support the same opacity parameter. Below, three filled triangles overlap with decreasing opacity.

fig = TikzFigure()

triangles = [
    ([(0, 0), (3, 0), (1.5, 2.5)], "red", 0.9),
    ([(1, 0), (4, 0), (2.5, 2.5)], "blue", 0.7),
    ([(2, 0), (5, 0), (3.5, 2.5)], "green!60!black", 0.5),
]

for pts, color, op in triangles:
    fig.draw(
        pts,
        cycle=True,
        fill=color,
        draw=color,
        opacity=op,
        line_width=1.5,
    )

fig.show()

Show the TikZ code

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \draw[fill=red, draw=red, opacity=0.9, line width=1.5] (0, 0) to (3, 0) to (1.5, 2.5) -- cycle;
    \draw[fill=blue, draw=blue, opacity=0.7, line width=1.5] (1, 0) to (4, 0) to (2.5, 2.5) -- cycle;
    \draw[fill=green!60!black, draw=green!60!black, opacity=0.5, line width=1.5] (2, 0) to (5, 0) to (3.5, 2.5) -- cycle;
\end{tikzpicture}

Show the standalone LaTeX document

\documentclass[border=10pt]{standalone}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{groupplots}
\usetikzlibrary{arrows.meta}
\begin{document}
% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \draw[fill=red, draw=red, opacity=0.9, line width=1.5] (0, 0) to (3, 0) to (1.5, 2.5) -- cycle;
    \draw[fill=blue, draw=blue, opacity=0.7, line width=1.5] (1, 0) to (4, 0) to (2.5, 2.5) -- cycle;
    \draw[fill=green!60!black, draw=green!60!black, opacity=0.5, line width=1.5] (2, 0) to (5, 0) to (3.5, 2.5) -- cycle;
\end{tikzpicture}

\end{document}

`fill_opacity` on path fills

Use fill_opacity on a path to make the fill semi-transparent while keeping the outline fully visible.

fig = TikzFigure()

import math

# A set of overlapping circles rendered as paths
for i in range(4):
    angle = i * math.pi / 2
    cx = 2 + math.cos(angle) * 1.2
    cy = 2 + math.sin(angle) * 1.2
    theta = [2 * math.pi * k / 40 for k in range(40)]
    pts = [(cx + math.cos(t), cy + math.sin(t)) for t in theta]
    colors = ["red", "blue", "green!70!black", "orange"]
    fig.draw(
        pts,
        cycle=True,
        fill=colors[i],
        draw=colors[i],
        fill_opacity=0.35,
        draw_opacity=1.0,
        line_width=2,
    )

fig.show()

Show the TikZ code

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \draw[fill=red, draw=red, draw opacity=1.0, fill opacity=0.35, line width=2] (4.2, 2.0)
        to
        (4.1876883405951375, 2.1564344650402307)
        to
        (4.151056516295154, 2.3090169943749475)
        to
        (4.091006524188368, 2.4539904997395467)
        to
        (4.009016994374948, 2.5877852522924734)
        to
        (3.9071067811865476, 2.7071067811865475)
        to
        (3.7877852522924735, 2.8090169943749475)
        to
        (3.653990499739547, 2.891006524188368)
        to
        (3.5090169943749476, 2.9510565162951536)
        to
        (3.356434465040231, 2.9876883405951378)
        to
        (3.2, 3.0)
        to
        (3.0435655349597694, 2.9876883405951378)
        to
        (2.8909830056250527, 2.9510565162951536)
        to
        (2.7460095002604534, 2.891006524188368)
        to
        (2.6122147477075273, 2.8090169943749475)
        to
        (2.4928932188134527, 2.7071067811865475)
        to
        (2.3909830056250527, 2.5877852522924734)
        to
        (2.3089934758116324, 2.4539904997395467)
        to
        (2.2489434837048465, 2.3090169943749475)
        to
        (2.2123116594048624, 2.156434465040231)
        to
        (2.2, 2.0)
        to
        (2.2123116594048624, 1.8435655349597693)
        to
        (2.2489434837048465, 1.690983005625053)
        to
        (2.3089934758116324, 1.5460095002604533)
        to
        (2.3909830056250527, 1.412214747707527)
        to
        (2.4928932188134523, 1.2928932188134525)
        to
        (2.612214747707527, 1.1909830056250525)
        to
        (2.7460095002604534, 1.1089934758116322)
        to
        (2.8909830056250527, 1.0489434837048464)
        to
        (3.043565534959769, 1.0123116594048622)
        to
        (3.2, 1.0)
        to
        (3.356434465040231, 1.0123116594048622)
        to
        (3.5090169943749476, 1.0489434837048464)
        to
        (3.653990499739547, 1.108993475811632)
        to
        (3.787785252292473, 1.1909830056250525)
        to
        (3.9071067811865476, 1.2928932188134523)
        to
        (4.009016994374948, 1.4122147477075266)
        to
        (4.0910065241883675, 1.546009500260453)
        to
        (4.151056516295154, 1.6909830056250523)
        to
        (4.1876883405951375, 1.8435655349597688) -- cycle;
    \draw[fill=blue, draw=blue, draw opacity=1.0, fill opacity=0.35, line width=2] (3.0, 3.2)
        to
        (2.9876883405951378, 3.356434465040231)
        to
        (2.9510565162951536, 3.5090169943749476)
        to
        (2.891006524188368, 3.653990499739547)
        to
        (2.8090169943749475, 3.7877852522924735)
        to
        (2.7071067811865475, 3.9071067811865476)
        to
        (2.5877852522924734, 4.009016994374948)
        to
        (2.4539904997395467, 4.0910065241883675)
        to
... (122 lines skipped) ...
        to
        (0.7999999999999998, 1.0)
        to
        (0.9564344650402308, 1.0123116594048622)
        to
        (1.1090169943749473, 1.0489434837048464)
        to
        (1.2539904997395466, 1.108993475811632)
        to
        (1.387785252292473, 1.1909830056250525)
        to
        (1.5071067811865473, 1.2928932188134523)
        to
        (1.6090169943749473, 1.4122147477075266)
        to
        (1.6910065241883678, 1.546009500260453)
        to
        (1.7510565162951535, 1.6909830056250523)
        to
        (1.7876883405951376, 1.8435655349597688) -- cycle;
    \draw[fill=orange, draw=orange, draw opacity=1.0, fill opacity=0.35, line width=2] (3.0, 0.8)
        to
        (2.9876883405951373, 0.9564344650402309)
        to
        (2.951056516295153, 1.1090169943749475)
        to
        (2.891006524188368, 1.2539904997395468)
        to
        (2.8090169943749475, 1.3877852522924732)
        to
        (2.7071067811865475, 1.5071067811865475)
        to
        (2.587785252292473, 1.6090169943749475)
        to
        (2.4539904997395467, 1.6910065241883678)
        to
        (2.3090169943749475, 1.7510565162951535)
        to
        (2.1564344650402307, 1.7876883405951378)
        to
        (1.9999999999999998, 1.8)
        to
        (1.8435655349597693, 1.7876883405951378)
        to
        (1.6909830056250525, 1.7510565162951537)
        to
        (1.546009500260453, 1.691006524188368)
        to
        (1.4122147477075266, 1.6090169943749475)
        to
        (1.2928932188134523, 1.5071067811865477)
        to
        (1.1909830056250525, 1.3877852522924732)
        to
        (1.108993475811632, 1.253990499739547)
        to
        (1.0489434837048464, 1.1090169943749475)
        to
        (1.0123116594048622, 0.956434465040231)
        to
        (0.9999999999999998, 0.8000000000000002)
        to
        (1.012311659404862, 0.6435655349597693)
        to
        (1.048943483704846, 0.49098300562505315)
        to
        (1.1089934758116318, 0.34600950026045335)
        to
        (1.190983005625052, 0.21221474770752702)
        to
        (1.292893218813452, 0.09289321881345258)
        to
        (1.4122147477075266, -0.009016994374947296)
        to
        (1.5460095002604528, -0.09100652418836774)
        to
        (1.690983005625052, -0.1510565162951535)
        to
        (1.8435655349597688, -0.18768834059513761)
        to
        (1.9999999999999996, -0.19999999999999996)
        to
        (2.1564344650402303, -0.18768834059513773)
        to
        (2.309016994374947, -0.1510565162951536)
        to
        (2.4539904997395463, -0.09100652418836797)
        to
        (2.5877852522924725, -0.009016994374947518)
        to
        (2.707106781186547, 0.09289321881345236)
        to
        (2.809016994374947, 0.21221474770752669)
        to
        (2.8910065241883673, 0.3460095002604531)
        to
        (2.951056516295153, 0.4909830056250524)
        to
        (2.9876883405951373, 0.6435655349597689) -- cycle;
\end{tikzpicture}

Show the standalone LaTeX document

\documentclass[border=10pt]{standalone}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{groupplots}
\usetikzlibrary{arrows.meta}
\begin{document}
% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \draw[fill=red, draw=red, draw opacity=1.0, fill opacity=0.35, line width=2] (4.2, 2.0)
        to
        (4.1876883405951375, 2.1564344650402307)
        to
        (4.151056516295154, 2.3090169943749475)
        to
        (4.091006524188368, 2.4539904997395467)
        to
        (4.009016994374948, 2.5877852522924734)
        to
        (3.9071067811865476, 2.7071067811865475)
        to
        (3.7877852522924735, 2.8090169943749475)
        to
        (3.653990499739547, 2.891006524188368)
        to
        (3.5090169943749476, 2.9510565162951536)
        to
        (3.356434465040231, 2.9876883405951378)
        to
        (3.2, 3.0)
        to
        (3.0435655349597694, 2.9876883405951378)
        to
        (2.8909830056250527, 2.9510565162951536)
        to
        (2.7460095002604534, 2.891006524188368)
        to
        (2.6122147477075273, 2.8090169943749475)
        to
        (2.4928932188134527, 2.7071067811865475)
        to
        (2.3909830056250527, 2.5877852522924734)
        to
        (2.3089934758116324, 2.4539904997395467)
        to
        (2.2489434837048465, 2.3090169943749475)
        to
        (2.2123116594048624, 2.156434465040231)
        to
        (2.2, 2.0)
        to
        (2.2123116594048624, 1.8435655349597693)
        to
        (2.2489434837048465, 1.690983005625053)
        to
        (2.3089934758116324, 1.5460095002604533)
        to
        (2.3909830056250527, 1.412214747707527)
        to
        (2.4928932188134523, 1.2928932188134525)
        to
        (2.612214747707527, 1.1909830056250525)
        to
        (2.7460095002604534, 1.1089934758116322)
        to
        (2.8909830056250527, 1.0489434837048464)
        to
        (3.043565534959769, 1.0123116594048622)
        to
        (3.2, 1.0)
        to
        (3.356434465040231, 1.0123116594048622)
        to
        (3.5090169943749476, 1.0489434837048464)
        to
        (3.653990499739547, 1.108993475811632)
        to
        (3.787785252292473, 1.1909830056250525)
        to
        (3.9071067811865476, 1.2928932188134523)
        to
        (4.009016994374948, 1.4122147477075266)
        to
        (4.0910065241883675, 1.546009500260453)
        to
        (4.151056516295154, 1.6909830056250523)
        to
        (4.1876883405951375, 1.8435655349597688) -- cycle;
    \draw[fill=blue, draw=blue, draw opacity=1.0, fill opacity=0.35, line width=2] (3.0, 3.2)
        to
        (2.9876883405951378, 3.356434465040231)
        to
        (2.9510565162951536, 3.5090169943749476)
        to
        (2.891006524188368, 3.653990499739547)
        to
... (132 lines skipped) ...
        to
        (0.9564344650402308, 1.0123116594048622)
        to
        (1.1090169943749473, 1.0489434837048464)
        to
        (1.2539904997395466, 1.108993475811632)
        to
        (1.387785252292473, 1.1909830056250525)
        to
        (1.5071067811865473, 1.2928932188134523)
        to
        (1.6090169943749473, 1.4122147477075266)
        to
        (1.6910065241883678, 1.546009500260453)
        to
        (1.7510565162951535, 1.6909830056250523)
        to
        (1.7876883405951376, 1.8435655349597688) -- cycle;
    \draw[fill=orange, draw=orange, draw opacity=1.0, fill opacity=0.35, line width=2] (3.0, 0.8)
        to
        (2.9876883405951373, 0.9564344650402309)
        to
        (2.951056516295153, 1.1090169943749475)
        to
        (2.891006524188368, 1.2539904997395468)
        to
        (2.8090169943749475, 1.3877852522924732)
        to
        (2.7071067811865475, 1.5071067811865475)
        to
        (2.587785252292473, 1.6090169943749475)
        to
        (2.4539904997395467, 1.6910065241883678)
        to
        (2.3090169943749475, 1.7510565162951535)
        to
        (2.1564344650402307, 1.7876883405951378)
        to
        (1.9999999999999998, 1.8)
        to
        (1.8435655349597693, 1.7876883405951378)
        to
        (1.6909830056250525, 1.7510565162951537)
        to
        (1.546009500260453, 1.691006524188368)
        to
        (1.4122147477075266, 1.6090169943749475)
        to
        (1.2928932188134523, 1.5071067811865477)
        to
        (1.1909830056250525, 1.3877852522924732)
        to
        (1.108993475811632, 1.253990499739547)
        to
        (1.0489434837048464, 1.1090169943749475)
        to
        (1.0123116594048622, 0.956434465040231)
        to
        (0.9999999999999998, 0.8000000000000002)
        to
        (1.012311659404862, 0.6435655349597693)
        to
        (1.048943483704846, 0.49098300562505315)
        to
        (1.1089934758116318, 0.34600950026045335)
        to
        (1.190983005625052, 0.21221474770752702)
        to
        (1.292893218813452, 0.09289321881345258)
        to
        (1.4122147477075266, -0.009016994374947296)
        to
        (1.5460095002604528, -0.09100652418836774)
        to
        (1.690983005625052, -0.1510565162951535)
        to
        (1.8435655349597688, -0.18768834059513761)
        to
        (1.9999999999999996, -0.19999999999999996)
        to
        (2.1564344650402303, -0.18768834059513773)
        to
        (2.309016994374947, -0.1510565162951536)
        to
        (2.4539904997395463, -0.09100652418836797)
        to
        (2.5877852522924725, -0.009016994374947518)
        to
        (2.707106781186547, 0.09289321881345236)
        to
        (2.809016994374947, 0.21221474770752669)
        to
        (2.8910065241883673, 0.3460095002604531)
        to
        (2.951056516295153, 0.4909830056250524)
        to
        (2.9876883405951373, 0.6435655349597689) -- cycle;
\end{tikzpicture}

\end{document}

Transparent vs white backgrounds

By default show() and savefig() produce a transparent PNG background (transparent=True). This is ideal for embedding the figure in slides or documents where the background color matters.

Passing transparent=False gives a white background — useful when the rendering environment does not support transparency. Note that setting transparent=False does not affect PDF output, which is always vector and relies on the viewer for background rendering. It also does not affect the Tikz code itself, which does not include any background rectangle by default.

fig = TikzFigure()

fig.node(
    (0, 0),
    shape="circle",
    fill="orange!60",
    content="Hello!",
    minimum_size="2cm",
)
fig.node(
    (3, 0),
    shape="rectangle",
    fill="teal!40",
    content="World!",
    minimum_width="2.5cm",
    minimum_height="1.2cm",
)

# Default: transparent PNG background (default transparent=True)
fig.show()

# White background
fig.show(transparent=False)

Show the TikZ code

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \node[shape=circle, fill=orange!60, minimum size=2cm] (node0) at ({0}, {0}) {Hello!};
    \node[shape=rectangle, fill=teal!40, minimum width=2.5cm, minimum height=1.2cm] (node1) at ({3}, {0}) {World!};
\end{tikzpicture}

Show the standalone LaTeX document

\documentclass[border=10pt]{standalone}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{groupplots}
\usetikzlibrary{arrows.meta}
\begin{document}
% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \node[shape=circle, fill=orange!60, minimum size=2cm] (node0) at ({0}, {0}) {Hello!};
    \node[shape=rectangle, fill=teal!40, minimum width=2.5cm, minimum height=1.2cm] (node1) at ({3}, {0}) {World!};
\end{tikzpicture}

\end{document}

# Saving examples (commented out — uncomment to run)
# fig.savefig("figure_transparent.png")          # transparent background (default)
# fig.savefig("figure_white.png", transparent=False)  # white background

The transparent flag only affects PNG output. PDF output is always vector and the background transparency is determined by the viewer.

Practical example: Venn diagram

A classic Venn diagram uses fill_opacity so the overlapping region inherits both colors visually.

import math

fig = TikzFigure()

R = 1.5  # circle radius
d = 1.2  # distance between centers

# Left circle
theta = [2 * math.pi * k / 80 for k in range(80)]
left = [(-d / 2 + R * math.cos(t), R * math.sin(t)) for t in theta]
right = [(d / 2 + R * math.cos(t), R * math.sin(t)) for t in theta]

fig.draw(
    left,
    cycle=True,
    fill="blue",
    draw="blue!80",
    fill_opacity=0.4,
    line_width=2,
)
fig.draw(
    right,
    cycle=True,
    fill="red",
    draw="red!80",
    fill_opacity=0.4,
    line_width=2,
)

# Labels
fig.node(
    -d / 2 - 0.6,
    0,
    content="Set A",
    draw="none",
    font=r"\bfseries",
    color="blue!80",
)
fig.node(
    d / 2 + 0.6,
    0,
    content="Set B",
    draw="none",
    font=r"\bfseries",
    color="red!80",
)
fig.node(
    (0, 0),
    content=r"$A \cap B$",
    draw="none",
    font=r"\small",
)

fig.show()

Show the TikZ code

% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \draw[fill=blue, draw=blue!80, fill opacity=0.4, line width=2] (0.9, 0.0)
        to
        (0.8953760005996919, 0.11768864359176742)
        to
        (0.8815325108927067, 0.23465169756034632)
        to
        (0.8585548805965147, 0.3501680457838581)
        to
        (0.8265847744427303, 0.46352549156242107)
        to
        (0.78581929876693, 0.5740251485476346)
        to
        (0.7365097862825519, 0.6809857496093201)
        to
        (0.6789602465311383, 0.7837478470739232)
        to
        (0.6135254915624212, 0.8816778784387097)
        to
        (0.5406089484000464, 0.9741720724952755)
        to
        (0.46066017177982144, 1.0606601717798212)
        to
        (0.3741720724952756, 1.1406089484000463)
        to
        (0.28167787843870973, 1.2135254915624212)
        to
        (0.18374784707392344, 1.2789602465311383)
        to
        (0.08098574960932026, 1.3365097862825517)
        to
        (-0.025974851452365222, 1.38581929876693)
        to
        (-0.1364745084375788, 1.4265847744427302)
        to
        (-0.2498319542161418, 1.4585548805965147)
        to
        (-0.3653483024396536, 1.4815325108927067)
        to
        (-0.48231135640823247, 1.495376000599692)
        to
        (-0.5999999999999999, 1.5)
        to
        (-0.7176886435917673, 1.495376000599692)
        to
        (-0.8346516975603459, 1.4815325108927067)
        to
        (-0.9501680457838579, 1.458554880596515)
        to
        (-1.063525491562421, 1.4265847744427305)
        to
        (-1.1740251485476345, 1.38581929876693)
        to
        (-1.28098574960932, 1.336509786282552)
        to
        (-1.383747847073923, 1.2789602465311385)
        to
        (-1.4816778784387097, 1.2135254915624212)
        to
        (-1.5741720724952755, 1.1406089484000466)
        to
        (-1.660660171779821, 1.0606601717798214)
        to
        (-1.7406089484000464, 0.9741720724952756)
        to
        (-1.8135254915624208, 0.8816778784387098)
        to
        (-1.8789602465311384, 0.7837478470739234)
        to
        (-1.9365097862825515, 0.6809857496093203)
        to
        (-1.98581929876693, 0.5740251485476349)
        to
        (-2.02658477444273, 0.4635254915624213)
        to
        (-2.058554880596515, 0.3501680457838583)
        to
        (-2.0815325108927065, 0.23465169756034648)
        to
        (-2.0953760005996918, 0.1176886435917676)
        to
        (-2.1, 1.8369701987210297e-16)
        to
        (-2.095376000599692, -0.11768864359176656)
        to
        (-2.0815325108927065, -0.2346516975603461)
        to
        (-2.058554880596515, -0.3501680457838579)
        to
        (-2.0265847744427306, -0.46352549156242034)
        to
        (-1.98581929876693, -0.5740251485476345)
        to
        (-1.936509786282552, -0.68098574960932)
        to
        (-1.878960246531138, -0.7837478470739236)
... (127 lines skipped) ...
        to
        (-0.613525491562421, 0.8816778784387098)
        to
        (-0.6789602465311383, 0.7837478470739234)
        to
        (-0.7365097862825517, 0.6809857496093203)
        to
        (-0.78581929876693, 0.5740251485476349)
        to
        (-0.8265847744427303, 0.4635254915624213)
        to
        (-0.8585548805965147, 0.3501680457838583)
        to
        (-0.8815325108927065, 0.23465169756034648)
        to
        (-0.8953760005996919, 0.1176886435917676)
        to
        (-0.9, 1.8369701987210297e-16)
        to
        (-0.8953760005996921, -0.11768864359176656)
        to
        (-0.8815325108927067, -0.2346516975603461)
        to
        (-0.858554880596515, -0.3501680457838579)
        to
        (-0.8265847744427307, -0.46352549156242034)
        to
        (-0.7858192987669302, -0.5740251485476345)
        to
        (-0.7365097862825519, -0.68098574960932)
        to
        (-0.6789602465311381, -0.7837478470739236)
        to
        (-0.6135254915624214, -0.8816778784387096)
        to
        (-0.540608948400047, -0.9741720724952748)
        to
        (-0.46066017177982144, -1.0606601717798212)
        to
        (-0.3741720724952762, -1.140608948400046)
        to
        (-0.28167787843870984, -1.213525491562421)
        to
        (-0.1837478470739229, -1.2789602465311387)
        to
        (-0.08098574960932037, -1.3365097862825517)
        to
        (0.025974851452365777, -1.3858192987669302)
        to
        (0.13647450843757863, -1.4265847744427302)
        to
        (0.24983195421614096, -1.4585548805965147)
        to
        (0.36534830243965344, -1.4815325108927064)
        to
        (0.48231135640823164, -1.495376000599692)
        to
        (0.5999999999999998, -1.5)
        to
        (0.7176886435917678, -1.495376000599692)
        to
        (0.834651697560346, -1.4815325108927067)
        to
        (0.9501680457838585, -1.4585548805965147)
        to
        (1.0635254915624208, -1.4265847744427305)
        to
        (1.1740251485476336, -1.3858192987669304)
        to
        (1.2809857496093198, -1.336509786282552)
        to
        (1.3837478470739226, -1.2789602465311387)
        to
        (1.4816778784387092, -1.2135254915624214)
        to
        (1.574172072495276, -1.1406089484000463)
        to
        (1.660660171779821, -1.0606601717798214)
        to
        (1.7406089484000464, -0.9741720724952752)
        to
        (1.8135254915624208, -0.88167787843871)
        to
        (1.878960246531138, -0.7837478470739242)
        to
        (1.9365097862825515, -0.6809857496093205)
        to
        (1.9858192987669296, -0.5740251485476355)
        to
        (2.02658477444273, -0.4635254915624214)
        to
        (2.058554880596515, -0.3501680457838578)
        to
        (2.0815325108927065, -0.23465169756034668)
        to
        (2.0953760005996918, -0.11768864359176712) -- cycle;
    \node[color=blue!80, draw=none, font=\bfseries] (node0) at ({-1.2}, {0}) {Set A};
    \node[color=red!80, draw=none, font=\bfseries] (node1) at ({1.2}, {0}) {Set B};
    \node[draw=none, font=\small] (node2) at ({0}, {0}) {$A \cap B$};
\end{tikzpicture}

Show the standalone LaTeX document

\documentclass[border=10pt]{standalone}
\PassOptionsToPackage{dvipsnames,svgnames,x11names}{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{groupplots}
\usetikzlibrary{arrows.meta}
\begin{document}
% --------------------------------------------- %
% Tikzfigure generated by tikzfigure v0.5.0     %
% https://github.com/max-models/tikzfigure      %
% --------------------------------------------- %
\begin{tikzpicture}
    \draw[fill=blue, draw=blue!80, fill opacity=0.4, line width=2] (0.9, 0.0)
        to
        (0.8953760005996919, 0.11768864359176742)
        to
        (0.8815325108927067, 0.23465169756034632)
        to
        (0.8585548805965147, 0.3501680457838581)
        to
        (0.8265847744427303, 0.46352549156242107)
        to
        (0.78581929876693, 0.5740251485476346)
        to
        (0.7365097862825519, 0.6809857496093201)
        to
        (0.6789602465311383, 0.7837478470739232)
        to
        (0.6135254915624212, 0.8816778784387097)
        to
        (0.5406089484000464, 0.9741720724952755)
        to
        (0.46066017177982144, 1.0606601717798212)
        to
        (0.3741720724952756, 1.1406089484000463)
        to
        (0.28167787843870973, 1.2135254915624212)
        to
        (0.18374784707392344, 1.2789602465311383)
        to
        (0.08098574960932026, 1.3365097862825517)
        to
        (-0.025974851452365222, 1.38581929876693)
        to
        (-0.1364745084375788, 1.4265847744427302)
        to
        (-0.2498319542161418, 1.4585548805965147)
        to
        (-0.3653483024396536, 1.4815325108927067)
        to
        (-0.48231135640823247, 1.495376000599692)
        to
        (-0.5999999999999999, 1.5)
        to
        (-0.7176886435917673, 1.495376000599692)
        to
        (-0.8346516975603459, 1.4815325108927067)
        to
        (-0.9501680457838579, 1.458554880596515)
        to
        (-1.063525491562421, 1.4265847744427305)
        to
        (-1.1740251485476345, 1.38581929876693)
        to
        (-1.28098574960932, 1.336509786282552)
        to
        (-1.383747847073923, 1.2789602465311385)
        to
        (-1.4816778784387097, 1.2135254915624212)
        to
        (-1.5741720724952755, 1.1406089484000466)
        to
        (-1.660660171779821, 1.0606601717798214)
        to
        (-1.7406089484000464, 0.9741720724952756)
        to
        (-1.8135254915624208, 0.8816778784387098)
        to
        (-1.8789602465311384, 0.7837478470739234)
        to
        (-1.9365097862825515, 0.6809857496093203)
        to
        (-1.98581929876693, 0.5740251485476349)
        to
        (-2.02658477444273, 0.4635254915624213)
        to
        (-2.058554880596515, 0.3501680457838583)
        to
        (-2.0815325108927065, 0.23465169756034648)
        to
        (-2.0953760005996918, 0.1176886435917676)
        to
        (-2.1, 1.8369701987210297e-16)
        to
        (-2.095376000599692, -0.11768864359176656)
        to
        (-2.0815325108927065, -0.2346516975603461)
        to
        (-2.058554880596515, -0.3501680457838579)
... (137 lines skipped) ...
        to
        (-0.6789602465311383, 0.7837478470739234)
        to
        (-0.7365097862825517, 0.6809857496093203)
        to
        (-0.78581929876693, 0.5740251485476349)
        to
        (-0.8265847744427303, 0.4635254915624213)
        to
        (-0.8585548805965147, 0.3501680457838583)
        to
        (-0.8815325108927065, 0.23465169756034648)
        to
        (-0.8953760005996919, 0.1176886435917676)
        to
        (-0.9, 1.8369701987210297e-16)
        to
        (-0.8953760005996921, -0.11768864359176656)
        to
        (-0.8815325108927067, -0.2346516975603461)
        to
        (-0.858554880596515, -0.3501680457838579)
        to
        (-0.8265847744427307, -0.46352549156242034)
        to
        (-0.7858192987669302, -0.5740251485476345)
        to
        (-0.7365097862825519, -0.68098574960932)
        to
        (-0.6789602465311381, -0.7837478470739236)
        to
        (-0.6135254915624214, -0.8816778784387096)
        to
        (-0.540608948400047, -0.9741720724952748)
        to
        (-0.46066017177982144, -1.0606601717798212)
        to
        (-0.3741720724952762, -1.140608948400046)
        to
        (-0.28167787843870984, -1.213525491562421)
        to
        (-0.1837478470739229, -1.2789602465311387)
        to
        (-0.08098574960932037, -1.3365097862825517)
        to
        (0.025974851452365777, -1.3858192987669302)
        to
        (0.13647450843757863, -1.4265847744427302)
        to
        (0.24983195421614096, -1.4585548805965147)
        to
        (0.36534830243965344, -1.4815325108927064)
        to
        (0.48231135640823164, -1.495376000599692)
        to
        (0.5999999999999998, -1.5)
        to
        (0.7176886435917678, -1.495376000599692)
        to
        (0.834651697560346, -1.4815325108927067)
        to
        (0.9501680457838585, -1.4585548805965147)
        to
        (1.0635254915624208, -1.4265847744427305)
        to
        (1.1740251485476336, -1.3858192987669304)
        to
        (1.2809857496093198, -1.336509786282552)
        to
        (1.3837478470739226, -1.2789602465311387)
        to
        (1.4816778784387092, -1.2135254915624214)
        to
        (1.574172072495276, -1.1406089484000463)
        to
        (1.660660171779821, -1.0606601717798214)
        to
        (1.7406089484000464, -0.9741720724952752)
        to
        (1.8135254915624208, -0.88167787843871)
        to
        (1.878960246531138, -0.7837478470739242)
        to
        (1.9365097862825515, -0.6809857496093205)
        to
        (1.9858192987669296, -0.5740251485476355)
        to
        (2.02658477444273, -0.4635254915624214)
        to
        (2.058554880596515, -0.3501680457838578)
        to
        (2.0815325108927065, -0.23465169756034668)
        to
        (2.0953760005996918, -0.11768864359176712) -- cycle;
    \node[color=blue!80, draw=none, font=\bfseries] (node0) at ({-1.2}, {0}) {Set A};
    \node[color=red!80, draw=none, font=\bfseries] (node1) at ({1.2}, {0}) {Set B};
    \node[draw=none, font=\small] (node2) at ({0}, {0}) {$A \cap B$};
\end{tikzpicture}

\end{document}

Opacity

opacity on nodes

fill_opacity vs draw_opacity

opacity on paths

fill_opacity on path fills

Transparent vs white backgrounds

Practical example: Venn diagram

`opacity` on nodes

`fill_opacity` vs `draw_opacity`

`opacity` on paths

`fill_opacity` on path fills