Enola Gay paint grenades are totaly bloody useless. They consist of a hollow cardboard grenade shape with a fuse on top that is lit like a regualr smoke bomb. Inside is a rather tiny plastic pouch of paint. When it is lit a few seconds later the grenade will explode open and one of two things will happen. Either, the pouch will magically get burst and eject a pathetic spray of paint over a very small area (usualy in one direction). Or the grenade will explode ejecting the pouch a couple of feet and not even burst at all.
The second eventuality is most common. Put simply, they are a total waste of time, effort and money. They make an okish bang but even that is weak compared to a good thunderflash.
Just avoid paint grenades entirely. A good smoke bomb is much more preferable, useful for gassing people out of holes, covering moves, setting fire to dry vegitation, creating atmosphere and also sometimes they smell wuite nice