Tetrachromacy is the condition of possessing four independent channels for conveying color information, or possessing four different types of cone cells in the eye. Organisms with tetrachromacy are called tetrachromats. In tetrachromatic organisms, the sensory color space is four-dimensional, meaning that to match the sensory effect of arbitrarily chosen spectra of light within their visible spectrum requires mixtures of at least four different primary colors. Most birds are tetrachromats. Tetrachromacy is also suspected among several species of fish, amphibians, reptiles, arachnids an...

Lilac is a color that is a pale tone of violet that is a representation of the average color of most lilac flowers. It might also be described as light purple. The colors of some lilac flowers may be equivalent to the colors shown below as pale lilac, rich lilac, or deep lilac. There are other lilac flowers that are colored red-violet. The first recorded use of lilac as a color name in English was in 1775. Variations of lilac Pale lilac At right is displayed the pale tone of lilac that is represented as lilac in the ISCC-NBS color list. The source of this color is sample 209 in t...