I have a response which is somewhat related. Although I have never painted a camera or had one painted, I have reskinned a number of cameras. The Yashica cameras made in Yashica/Contax mount had notoriously poor coverings. When they were new they were fine but they did not age well.
The coverings would blister and peel off leaving what felt like canvas and looked dull gray in color. I thought about what materials I might use and I came up with textured vinyl floor tread material. The material has adhesive backing. My repairman stripped off the adhesive backing and used Pliobond to attach the new covering. The cameras I had him cover were mostly Yashica FX-3s with at least one FX-3 Super. The FX-3 Super 2000 was made with a hard material which aged better. What colors did I use? Black, light gray, medium gray and white. I thought something like red or yellow would be too garish. When the cameras were re-covered, they were also overhauled. While the FX-3 is somewhat primitive with its meter button on the back of the top plate, it has a very nice finder, an accurate meter and seems to hold up. My one disappointment is with the very handsome FX-3 Super, which has the medium gray covering. The mirror in the FX-3-Super sticks out just slightly more than the one in the regular FX-3. It won't work properly with my 60/2.8 S-Planar. I have a number of 55/2.8 Yashica ML Macro lenses and they work properly with the FX-3 Super.
In a related matter, I have a black Canon FX. It is my understanding that very few Canon FX cameras were originally black. Some were later painted black. I would still like to have a reliable source for knowing whether my FX was originally black or later painted black. It looks original to me.