Skitarii Robes Question

Hey all. I'm building a mixed Dark Angels and mechanicum list and want to tie the troops together somehow via the colour scheme. I was thinking of painting the skitarii robes green.

My question, as I've never played mechanicum before, is what is the significance of the troop colors? Fluff wise - would it make sense that skitarii and other mech forces adopted the colors of their allies as a mark of respect, or is that not their style?