C4 has a red light top middle on it already just like mines. You can't throw C4 like you can throw grenades. If they landed C4 in the middle of your group, they're close enough to shoot with a shotgun, or are hovering above you which is something else you should be watching for anyways if you don't have a roof over you. If you can't see an enemy infantry run up withing 6 feet of you and throw C4, then you shouldn't get a big bright glowing brick. Especially with the delay on detonation.
