Standardize the colors through the IF, and bam, you can tell at a glance what a cable is capable of.
Like resistors, except I don't think cables are likely to shrink too much in the future.
I will say, they're not alone. Look at Razer, for instance. Electric green is not exactly a part of the USB 3 standard.
If it's a cable property, then Apple can do whatever it wants with its cables. And everyone else can do what they want with theirs.
I think what we've learned throughout the years is that your color coding idea doesn't work out in practice due to an earlier comment stating that the USB-C market being bottom-feeder. There has to be an exact, rigid specification of USB-C cables that all of them should follow (i.e. USB4/TB4). Any more complicated than that like color coding results in giant scams by manufacturers, outright wrong, or impossible-to-find cables on an eCommerce search engine. I just don't want to deal with any of those anymore. It feels so much nicer right now to look up TB4 on AliExpress and be done with it, no more worrying or guessing.