Quote Originally Posted by Sonic Mountain View Post
...that looks like a bit of pigment that wasn't fully mixed in, putting the clear on may have 'reactivated' it and brought it to the surface...
That would be my guess as well. It's one of the perils of rattle can finishing IME.
I've had it happen and the only fix I found is re-spraying it. You don't need to sand it all the way back, just shoot the base colour over it, then re-coat with your clear.
It can be done as a spot repair but that can be tricky with spray cans. I did it once by re-applying the colour coat in the affected area; levelling it out with 1200; then re-spraying the entire thing with my clear.

Like I said, it *can* be done, but not always easy.

That'll be 2 cents, please