Probably an Ocellaris. Ocellaris clowns darken just like that with age, as where percs dont. As percs grow, the black lines along the white thicken big time. The darker one, that looks a lot like yours is actually an ocellaris clown. Not a percula, as it would appear to be, and I assume you have a similar situation. If you ask me, you've got an ocellaris. Believe it or not, in that pic of mine, the bright orange one, which you'd think is an ocellaris, is actually a percula, and the dark one, that looks like a percula, is actually an ocellaris.