Keep in mind some states outlawed bobber cabooses pretty far back. Here in Minnesota, the Railroad Act of 1911 (IIRC) required cabooses to be at least 24' long and have at least two four-wheel trucks. So I suspect relatively few bobbers were around long enough to get colorful post-war type decoration.
BTW the Missabe Road's classic wood cabooses, as modelled in HO by Walthers, were the result of the railroad taking two bobbers and combining them into one caboose so they met the legal requirements. You can see how it was originally a bobber with the cupola between the two windows, and then they added the non-cupola part of another one with one window to get it to length.
https://www.trains.com/wp-content/uploads/2020/10/mrr-pr0710_13.jpg
Cabooses are painted whatever the standard is for the railroad, 4 wheel or 8 wheel. If the railroad had bobber cabooses they would be painted standard railroad colors for the time.
Dave H. Painted side goes up. My website : wnbranch.com
I have a bobber caboose that I got in a box of used trains. It's just cheap sheet metal, painted red. I've never run it. It has one horn hook. The caboose has no markings.
It takes an iron man to play with a toy iron horse.
I havent seen anything written either that indicated anything other than red or boxcar red.
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
What colors did exist on Bobbers? Pretty much all the colors on all other types of cabooses. What ever the railroad had on hand that was cheapest, easiest to do, and follows some sort of protocol if need be.
PMR
Most cabooses are a form of red or boxcar red, bobbers no exception. There are some color schemes from that era on standard cabooses, so was the same true for bobbers? UP had its yellow red on bobbers too. Google yields only black and white photos. And loads of models. What colors did exist on bobbers?
shane