Cool hair tones, hues that are not part of the warm spectrum of colors, have been a trend for centuries. These can be seen in colors ranging from light brown to black, and even unnatural colors such as blue and purple.
Cool hair tones are often seen in people with naturally dark hair, and can be achieved through the use of hair dye or bleach. The trend of cool hair tones has been around for centuries, and can be seen in paintings from the Renaissance period and onwards.