During the team creation phase of matchmaking, just before the match begins, different players will be highlighted in red. Seems like I've seen some highlighted in blue, too. Not everyone in the lobby will be highlighted, though. Some that are highlighted will have the highlight go away. Some that are not highlighted will suddenly be highlighted. At first I thought this was some sort of indication that the players were in a party, but that does not always seem to be the case either.
So what do the colors highlighting players during the matchmaking / loading mean?