I guarantee that having a yellow school bus is more of a liability than its worth.
Busses painted up in graffiti, hand painted hippy stuff will most likely bring attention that's potentially negative. I believe in hiding in plain site & not arousing confrontation with the cops. A 40' bus boondocking in a parking lot is hard to miss. Some cops will specifically target hippy type busses. Once your pulled over for either the traffic arm, the word school bus or the yellow paint. Its not improbable for them to check for seatbelts, ids for all occupants. Its common once at the door for them to lie about smelling illegal substances to gain probable cause to search the whole vehicle. There are plenty of burners that get targeted & ticketed while traveling to & from Black rock city every year.
The problem is that the cops will have enough ammo to issue a ticket that may require a court date & towing. There are lots of partially converted school busses around in various stages of conversion. If you notice that most of them that were done right with plumbing, hookups, generator with ac power, solar, heaing/ac are always painted other than yellow. It gets damn expensive converting a bus as you are probably well aware of at the moment. It all depends on how well you want to protect your investment. One ticket or tow will be much more cash then a diy paint job.
I know it sounds like I am some old fogey worry wart. I just limit my risks is all. I am not trying to be preachy either. In the end its your bus, sweat equity & money invested in it. I/we don't even know if you plan to travel throughout the lower 48 with it or just use it as a residence in the PNW. Paint is cheap. getting harassed by multiple cops gets expensive.