When Fred is trying to figure out what kind of talent Pebbles has after Barney points out that the others are being judged by their talent, Pebbles has her bathing suit on. Then when Pebbles is crawling onto the stage when it's her turn and Dino starts running to get her, she has her regular clothes on. Then when she's on the stage with Dino, she has the bathing suit on again.
Towards the end of the contest, Pebbles is shown wearing a green swimsuit, then her usual clothing, then back to the swimsuit.
When filling out the beauty contest form Fred says that Pebbles hair color is brown, when it is obviously red.