That's really nice!
I have red, green, blue and violet in my projector as well. I started out thinking I would write code to independently control the violet as a forth, discrete color, but I also wired my projector with a switch so that the violet could get it's signal from the blue channel.
So far, I haven't done a whole lot with that idea.
Still, it is fun to scan in pure violet onto glow-in-the-dark paper!
The green laser I just got is quite a bit brighter than the other colors and I adjusted it with the gain control of the green channel on the LaserBoy correction amp. The linearity is not exactly right, but once I got it adjusted down a little, it's not bad at all.
James.