Something like that was tried with usb 1.1, 2, and 3, being white/black/blue. But many manufacturers got very loosey-goosey with it.

I'm sure it'd be worse as soon as a common spec for this popped up for USB-C.

Yeah, that was actually quite helpful (when properly implemented). Especially in era of laptops that had a mixture, you knew to plug in the portable drive into blue not the black USB port (and put your phone to charge into yellow one:).

Yellow (always supplies power) was non standard, as was green. Would have been nice if that was included in an addendum to the USB spec though.