I bought a blow mold at a rummage sale a year ago, planning to sell it at a bargain price, because of its condition. It was a black cat sitting on a jack-o-lantern and the orange on the pumpkin was faded to almost white.
I decided to keep the cat & pumpkin and paint the pumpkin a renewed orange (thinking that new granddaughter might like it in a couple of years).
I've seen blow molds that people have brush painted and you can always see the brush strokes -- they look really bad. I bought Rustoleum spray paint that is made to bond to plastic. The toughest decision was neon or regular orange? Since I could barely see the old finish, it was impossible to know which it had originally been! I opted for regular, as the neon was too much like landscaper's orange...
I didn't take a good before picture, because I thought I already had one... The pumpkin was almost the color of the cat's mouth, though. I think that was originally orange, too, but I didn't try to paint it.
Taping off all the black and masking the cat was the biggest part of the job (it took almost a half hour to make sure it was perfect.
I made sure it was completely covered, but didn't want it to be too opaque.
I think it turned out pretty well! Now all I need is the granddaughter! :-)