When Mother finds Pollywog outside the house, her dress is cerulean and apron is lavender. Then, when she calls for her daughters, her dress is lavender and apron, cerulean. Afterwards, as she's seen with her son and daughters in another scene, the colors of her dress and apron are back to being the other way around.
When the butcher touches a disguised Peter's right arm, he rubs off some of the green paint. But then his right arm is seen covered in green paint entirely again, just before Penny tackles him from behind, thinking he's actually another one of the green people.
When the green people confront Peter about killing Long John Silver (though it is just a game and the weapon used is a toy gun), the Mayor's nose is green. But in the next scene featuring him, his nose is magenta again.