not really sure

#1
ok i went to the dentist today to get my braces:( and they have a saltwater aquarium as do most of the dentist ive been to.they have a fish that i dont know what it is and neither do they.it was blue with purple stripes and its fins where a rusty orange color.it had missing scales around its back fin.is it sick.do you know what type of fish it could possaibly be