The `hue (H), saturation (S), value (V) color model`__ is an intuitive way of specifying colors. Internally PGF only supports the RGB, CMY, CMYK and Gray color models, but xcolor can automatically convert from HSV to your target color model.

This illustration shows samples of the HSV color space and how they relate to the RGB color model. The saturation and value parameters are set to S=V=1.

Docutils System Messages

System Message: ERROR/3 (./rgb-color-mixing.txt, line 14); backlink

Anonymous hyperlink mismatch: 1 references but 2 targets. See "backrefs" attribute for IDs.

Edit and compile if you like:

% RGB color mixing
% Author: Henrik Skov Midtiby 
\documentclass{article}
% Set target color model to RGB
\usepackage[rgb]{xcolor}
\usepackage{tikz}


\begin{document}

\begin{tikzpicture}
% Create the background in the circle, by drawing several slices
% each with a constant color given by the angle (which is converted
% to a color usin the hue, saturation and brightness color space).
\foreach \x in {0,0.0111,...,1} {
	\definecolor{currentcolor}{hsb}{\x, 1, 1}
	\draw[draw=none, fill=currentcolor]
		(-360*\x+88:2) -- (-360*\x+88:3.8)
		-- (-360*\x+92:3.8) -- (-360*\x+92:2) -- cycle;
}

% On top of the background draw three spotlights of the primary colors
% red, green and blue (they are primary in an additive colorspace where
% light are mixed)
\draw [draw=none, fill=red] (90:1.5) circle (2cm);
\draw [draw=none, fill=green] (-30:1.5) circle (2cm);
\draw [draw=none, fill=blue] (210:1.5) circle (2cm);

% Draw areas where two of the three primary colors are overlapping.
% These areas are the secondary colors yellow, cyan and magenta.
\begin{scope} % red + green = yellow
	\clip (90:1.5) circle(2cm);
	\draw [draw=none, fill=yellow] (-30:1.5) circle (2cm);
\end{scope} % blue + red = magenta
\begin{scope}
	\clip (210:1.5) circle(2cm);
	\draw [draw=none, fill=magenta] (90:1.5) circle (2cm);
\end{scope}
\begin{scope} % green + blue = cyan
	\clip (-30:1.5) circle(2cm);
	\draw [draw=none, fill=cyan] (210:1.5) circle (2cm);
\end{scope}

% Draw the center area which consists of all the primary colors.
\begin{scope} % red + green + blue = white
	\clip (90:1.5) circle(2cm);
	\clip (210:1.5) circle(2cm);
	\draw [draw=none, fill=white] (-30:1.5) circle (2cm);	
\end{scope}

% Draw a circle with markings along the perimeter, indicating which angles
% the hue function connects to certain colors.
\draw (0, 0) circle (3.9cm);
\foreach \x  in {0, 30, ..., 330}
	\draw (-\x+90:3.8) -- (-\x+90:4.0) (-\x+90:4.4) node {$\x^\circ$};

% Add labels with names of the primary and secondary colors.
\foreach \x/\text in {0/red, 60/yellow, 120/green, 180/cyan, 240/blue, 300/magenta}
	\draw (-\x+90:5.5) node {\text};
\end{tikzpicture}


\end{document}

Click to download: rgb-color-mixing.tex • rgb-color-mixing.pdf
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