The Koi Angelfish. Koi angelfish must be fed foods high in carotene to keep and show off their orange/red colors. Our Koi's were sourced from the best Koi Angelfish breeders we could find. Also known as HR Koi's from other sellers, these are the premium of all Koi Angelfish. These are pre-dime. about 4 weeks old. in 3 more weeks will be dime size. This will be a mix of Standard and veils (mostly veils) and there will be some Super Red Spotted Koi's in the mix.