Pygmy angelfish of the genus Centropyge can change color and appearance dramatically from juvenile to adulthood. Like most marine fish, their adult coloration can also change quite a bit depending on their captive aquarium environment. In the past when aquarium fish food and nutrition was relatively poor and little understood, many Centropyge and other marine fish would fade and become less colorful with age and duration in captivity.
Now that the marine aquarist has access to a wide range of quality feeds, fading of reef fish colors is much less of an issue but with more Centropyge growing old in brightly lit reef tanks, Pygmy Angelfish owners are witnessing that many Centropyge can become much darker under high intensity reef aquarium lighting. The video above shows an average male Centropyge potteri which is a resident of a 1500 gallon reef tank that was installed and is maintained by AquaticArt Inc. of Denver Colorado. 
After less than a year living in this aquarium that is lit with multiple 1000 watt metal halide lamps, this fish has quickly developed a much darker coloration than we have ever seen for a potter’s angelfish. By contrast another C. potteri living in a very dimly lit 900 gallon fish aquarium also maintained by AquaticArt has a much paler coloration than a typical fresh-caught potter’s angelfish.
Kyoshi Endo’s great book Angelfishes of the World also documents the darkening of A Centropyge multicolor: before and after images of a specimen clearly demonstrates the development of a yellowish tan dorsal body color where the body used to be white after this fish was kept in a brightly lit reef aquarium. This image of a multicolor angelfish on Vivid Aquarium’s website shows a specimen which is clearly way darker than a wild specimen would be, probably from living in a brightly lit, shallow water reef tank. The darkening of Centropyge Pygmy Angelfish may not apply to all species but there is a strong record of certain species changing color due to intense lighting conditions.
