I'm getting the feeling our argument is more rooted in a scientific (physics of light) vs artistic (color theory) viewpoint so I'll leave it alone. We can both be considered to be correct. In the use of paints and dyes etc, yes you will achieve a black color through combination, but on the subject of light, black is the absence of color while white is the presence of all color (or absorption vs reflection) I simply was hoping to help AardWolf wih her character idea.

Regarding the green plants, I'll have to see about finding the article I read years ago, but there was some study making the claim that the planet used to be purple rather than green, the explanation included the energetic component of RGB light, and stated the majority of usable energy for photosynthesis was in the green spectrum of light - yes violet aka ultraviolet is the highest energetic spectrum of light but it also damages DNA. Which would be another evolutionary benefit to purple leaves come to think of it.

And finally on the subject of evolution, no, it does not imply the best solution, simply the one that wasnt an evolutionary dead end. One would think though, that if plants did have purple leaves, they would be more dominant than green plants, leading one to wonder why they all died out. Assuming this article I read was correct. Again, I'll see about finding it. I'll pm you it if you'd like (If I can find it) but we should probably avoid derailing this thread further.