The color blue is associated with two of Earth’s greatest natural features: the sky and the ocean. But that wasn’t always the case. Some scientists believe that the earliest humans were actually colorblind and could only recognize black, white, red, and only later yellow and green. As a result, early humans with no concept of the color blue simply had no words to describe it. This is even reflected in ancient literature, such as Homer’s Odyssey, that describes the ocean as a “wine-red sea.”

Blue was first produced by the ancient Egyptians who figured out how to create a permanent pigment that they used for decorative arts. The color blue continued to evolve for the next 6,000 years, and certain pigments were even used by the world’s master artists to create some of the most famous works of art. Today it continues to evolve, with the latest shade discovered less than a decade ago. Read on to learn more about the color’s fascinating history.

There’s a long list of things we can thank the ancient Egyptians for inventing, and one of them is the color blue. Considered to be the first ever synthetically produced color pigment, Egyptian blue (also known as cuprorivaite) was created around 2,200 B.C. It was made from ground limestone mixed with sand and a copper-containing mineral, such as azurite or malachite, which was then heated between 1470 and 1650°F. The result was an opaque blue glass which then had to be crushed and combined with thickening agents such as egg whites to create a long-lasting paint or glaze.

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