Watch the Vidoc. Then, analyze the multiplayer characters. They each have white lines around their blue/red armor. Could this confirm that secondary colors are visible in team games? Perhaps 343 had every player put on the same secondary color (white) for the Vidoc, because otherwise it doesn’t make sense for the team’s color to have white in the design by default.
As long as we can actually change the color of those white lines I’ll be happy. I hated how all of the armor in Reach had permanent white lines and shapes on them.