Color blindness all variations in human color vision involve the red and green receptors in male eyes. It is very rare for males or females to be "blind" to the blue end of the spectrum. The first scientific paper on the subject of color blindness, "Extraordinary facts relating to the vision of colours", was published by the English chemist John Dalton in 1798 after the realization of his own color blindness. Because of Dalton's work, the general condition has been called "daltonism", although in English this term is now used only for deuteranopia. Color codes present particular problems for those with color
Citrine (colour) 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 yellow, greenish-yellow, brownish yellow or orange. The original reference point for the citrine colour was the citron fruit. The first recorded use of "citrine" as a colour in English was in 1386. It was borrowed from a medieval Latin and classical Latin word with the same meaning. In late medieval and early modern English the citrine colour-name was applied in a wider variety of contexts