Some other parrot species produces a third pigment named advanced-psittacin which enables color & tones ranging from oranges, peaches, pinks to reds.
When these feathers are exposed to a white light source, such as sunlight, only the blue part of the spectrum is reflected by the eumelanin granules.
The many color variations of budgerigars, such as albino, blue, cinnamon, Clearwinged, the various Fallows, Grey, Greygreen, Greywing, Lutino, Mauve, Olive, Opaline, Spangled, Suffused and Violet are the result of mutations that have occurred within specific genes.
As is true with all animal species, color mutations occur in captivity as do in the wild.
This has been demonstrated when captive-bred budgerigars have developed mutations that had only been previously recorded amongst wild populations.