False percula is an ocellaris.
Perculas grow to be slightly smaller than ocellaris. Perculas turn out to be more of a yellow-orange, while ocellaris are usually deep orange or brownish-orange. Perculas have more black surrounding the white stripes, and ocellaris have thin black lines surrounding their white stripes.
IMO, they are nearly the same fish, just different appearances.
There are a lot of variants too: black/white ocellaris, snowflake, picasso, jigsaw, onyx perculas, black, etc..