Like the (brief) period when the sense of traffic lights was changed, so that "red" indicated "go". This makes perfect sense, since anything red must of course stand for making progress.
I wonder if it's a subtle psychological trick to not associate red with negative connotations (such as "declining profits", "stop", "blood") because the color red is part of the CPC's identity makeup.Or maybe it's just a cultural thing, like how they wear white when someone died and black to celebrate a birth/life (I'm not sure if it is a chinese custom however, but I know it's an asian custom).