Pyxplot 
Examples  RGB color mixing 
Using the color map plotting style to produce an arbitrary color image (I) Here the colormap plotting style is used to produce an arbitrary color distribution in the xy plane. Two values are passed to the color expression specified using the set colormap command; c1 equals the first plotted expression, x, while c2 equals the second plotted expression, y. These coordinates are then used to produce three circular pools of red, green and blue light, which overlap to show how the mix together. The function t(r) is used to soften the edges of the pools of light, to look more natural. Scriptset size 7.5 square set nokey set nocolkey set numeric errors quiet set noxtics ; set noytics set axis x invisible set axis y invisible d = 0.5 t(x) = max(0,2exp(x**8)) set colmap rgb(t(hypot(c1 ,c2d/sqrt(2))), \ t(hypot(c1+d,c2+d )), \ t(hypot(c1d,c2+d )) ) set sample grid 250x250 set c1range norenorm set c2range norenorm plot [1.5:1.5][1.5:1.5] x:y with colormap
