In South Korea, buses are color-coded to let travelers know what kind of bus it is (long distance, feeder route, express, circular). On top of that, they divided the city into 8 zones, and number the buses based on how they travel between zones with the bus's ID as the last digit. So for example, bus 048 travels from zone 0 to zone 4 and is ID# 8. Very simple system for people to get around, especially if they don't speak Korean.
Could TriMet do something like that here?