Pigeon Blood Discus

Silent Death and the Fake Smile (Fake Well-being Futile Deaf Mute):

In normal Discus, stress is immediately noticed because the fish turns black. The Pigeon Blood, lacking this ability, will mask the pain. You could have a fish severely ill with gill flukes or flagellates that still appears bright yellow. The only indicator will be heavy breathing and feces. When a Pigeon lies on the bottom, it is usually too late to save it.

The Peppering Condemnation (Dirty Fish Syndrome Futile Blind):

If you set up a modern design aquarium, with black volcanic sand and dark backgrounds, to make a Pigeon Blood Discus stand out... you will make a fatal mistake. For osmotic camouflage, the fish will explode its excess melanin. Your bright orange fish will be covered in horrible black spots, looking like it rolled in soot (Extreme Peppering). They will never go away. To have a "clean" Pigeon, you must keep it in an almost sterile environment: pristine white sand, no black backgrounds, and zero stress.