Einstein A5
Russian Elite D3 (well, not pure black. As PD says, it is perfectly possible to use "black" as long as its light enough to read the text with a black background. I use 0,0,75 myself).
Yuri Revolution F4 (almost GDI Gold)
Civic Republic Either D2 or something even brighter - as close to white as possible without it being confused with white itself.
Reasons? Because I think these colours suit their teams, 'nuff said
