Citrine (colour) than it is today and could be "reddish or brownish yellow; or orange; or amber (distinguished from yellow)". In today's English citrine as a colour is mostly confined to the contexts of (1) gemstones, including quartz, and (2) some animal and plant names. E.g., the citrine wagtail ("Motacilla citreola"), an Asian bird species with golden-yellow plumage, or the citrine warbler, citrine canary-flycatcher, citrine forktail, etc. Citrine (colour) Citrine is a colour, the most common reference for which is certain coloured varieties of quartz which are a medium deep shade of golden yellow. Citrine has been summarized at various times as
Budgerigar colour genetics Budgerigar colour genetics The science of budgerigar colour genetics deals with the heredity of mutations which cause colour variation in the feathers of the species known scientifically as "Melopsittacus undulatus". Birds of this species are commonly known by the terms 'budgerigar', or informally just 'budgie'. The wildtype (natural-coloured or wild occurring) budgerigar's colour is called Lightgreen. The feathers of most parrot species, including budgerigars, contain both a black type of "melanin" named "eumelanin" along with a basic yellow pigment named psittacofulvin (psittacin for short). Some other parrot species produces a third pigment named advanced-psittacin which enables colour & tones ranging