You can turn on squad highlights....then you can choose a color for your squads....or to whom you are tuned on vox.......default is blue, i think.
Wingman, one, can be set as well.....shows white by default.
That all makes sense, since you'd be in radio contact with these people, and therefore, know where they are....
You wouldn't know one enemy (Knits) from another (Bish) so they all show red (default) on dar.