Colors

[Shaderboy]

Hey, I wanted to be able to use colors with the particles, and I saw some other people were trying to figure out the same thing. I figured it was worth making a pull request. This branch only has a couple of lines added to the addon itself, but maybe more importantly it includes an example for adding color from a mask image. Other than that, it's the same as the base example. Check it out:

Let me know what you think!