I caught a white PPP when the requirement for the quest was a double premium white, so this should have completed. The appaloosa patterns shouldn't matter, right? I've completed White capture quests with appy whites before.

I could be wrong but I know there are a couple quests that won't complete if they say double premium and you caught a triple premium. If I remember correctly this is one of them.

I think Angel is right I'm 80% sure you need PP only not PPP for it count >.> It's sorta frustrating

I had the same yesterday- pretty sure its PP only for this one

Got it. I hate this. Same with the "breed a premium X" - should complete if it's premium or better. Makes no sense that I captured a PPP and it can't complete a double premium quest because there's one extra P instead of a lower rating.