Dude, WTAF?!?!! I’ve seen that posted in this thread, and otherwise, like - at least a million times.
Guys that own swords don't have wives. They have selfies with Dragon Con cosplay ringers that they rub out to. That's the work of a guy pissed off at his DM for a bad saving throw.
Black absorbs light white reflects it, the scanner uses light to read (see) the barcode, so the white is the better option