i just realised i kind of took this way off-topic.. my apologies
Multicam will work great, if it's on it's own team... usually it doesn't work so great when players are forced to distinguish it from other misc patterns, such as DESPAT, ACU, MARPAT, then you can throw in 3-color DCU, BDU's, some random russian shit, contractor colors, some douche-bag wearing jeans and a tshirt
bottom line is, having solid uniform requirements would eliminate the whole friendly-fire issue. other then that, Multicam is great imo
the best way is to just tie a colored band around each player's arm, two colors; one for each team. red/blue works great..