Blue sapphires are evaluated based upon the purity of their primary hue.

But Aristotle's notion of seven basic colors - with primary hues, related to the four elements - held sway through the Renaissance.

Dizzying constellations, cold fire in every primary hue.

Humans perceive white light as the mixture of the three additive primary hues: red, green, and blue.

Congenital color vision deficiencies are subdivided based on the number of primary hues needed to match a given sample in the visible spectrum.

Its primary hue is red, a color that rivets the eye.

The aft corner of the corridor were marked with more of the alien script, these in vivid primary hues.

Emeralds occur in hues ranging from yellow-green to blue-green, with the primary hue necessarily being green.

Transparent gemstones occur in the following primary hues: red, orange, yellow, green, blue, violet.

In ruby the primary hue must be red.