yeah, chocolate is the name used to describe a variation of angelfish color that displays a lighter dark brown shade, that as you can see on the belly of your angelfish, even covers the white and silver parts.
A true black angelfish has a much darker black charcoal color with a velvety texture rather than clear brown.
I've got an adolescent marbled angel in my 180g "large community" tank. I plan on getting more angels... koi... black... zebra... and gold.