If colour was influencing the game, it would be in player mindset and game developer thought, not in statistical game play.
Typical Red armies:
Other Red Marines
Other Red CSM
Eldar Fire Dragons
Speed Freak/Evil Sunz orks
All of these armies are typically assault or aggressive play focussed, but aren't necessarily armies that are associated with winning very often. If the colour bias was in effect, it appears to be at a game developer level with red units more aggressive, but not necessarily better for game play.
Interesting mental exercise, nice question.