According to this diagram, if we have both red and blue light mixed together we should get a violet light.
Modify your code to create the following colored light: Violet (red & blue), Turquoise (blue & green) and yellow (green & red)
Actually, red + blue light = magenta and blue + green light = cyan. I dunno, I'm geeky enough that I'd have liked the actual names to be used, or a footnote explaining the actual colors. It's not entirely trivial because what's going on is that mixing the additive primaries yields the subtractive primaries.