I also agree with the spirulina as being the best color enhancer--for the most brilliant orange.
Of course if you have a white fish--it will make yellow or gold areas so it is best for orange fish.
In my signature, you can see my two orange fish--very bright orange from spirulina flakes from Goldfish Connection but my white telescope now has a yellow head, gold over her eyes and gold pectoral fins. She used to be completely white.