> There's no colour scheme that can adequately handle all the possible variations.

For cables, you can whittle it down to two things. Bandwidth, and whether it supports 3 amps or 5 amps. Supported modes is a function of signal bandwidth. 5 amp can be a little power icon, and bandwidth only needs about 3-4 options. So most cables would only have a bandwidth rating.

For ports I agree that it's much too complicated.