The Aliatoc color scheme was my first exposure to the 40k universe. I really just wanted to learn to paint minis, so I went down to the comic shop and picked up a few Eldar. It took me a little while to realize that half of what I picked up was epic scale, and that the Avatar was a huge monstrocity and not a cute Eldar midget.
Anyway, the color scheme has evolved over time. Two different clients actually send me the same concept for a color scheme here, so I thought I'd show them off together.
And a Titan that wasn't part of the same group: