The exterior of the USB A connector stayed the same. The number of pins increased when we went from USB 2 to 3. So, even in this case, it’s slightly more complicated. The colors helped because the capabilities were very different between the ports. But when the USB IF increased the number of options (and reduced the size of the connector), different colors became impossible to do.

The problem is that there are too many uses for one connector. But this is wha we wanted - a reduced number of standardized connector/power options.