When playing with frinds you are in a party with, their arrows show up as blue instead of green.
I would be beneficial to know which blue arrow is which player in my party.
Color coding players, to me, would be too distracting. What if you could put single digit numbers in each blue arrow? Each player could assign numbers to the players they play with most frequently through the barracks, etc.
I imagine there are multiple ways to achieve the same result, but this concept would be a great asset to the multiplayer gaming aspect of MW3!!