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
Colour centre colour centre begins in V1 and sends signals to extrastriate areas V2 and V4 for further processing. V4 in particular is an area of interest because of the strength of the colour receptive fields in its neurons. V4 was initially identified in macaque monkey visual cortex experiments. Originally, it was proposed that colour was selectively processed in V4. However, this hypothesis was later rejected in favour of another hypothesis which suggested that V4 and other areas around V4 work together to process colour in the form of multiple colour selective regions. After identification of V4 as the colour-selective region in