Blue Morpho Butterfly

Lore & Background

Blue has been important in art and decoration since ancient times. Lapis lazuli was used in ancient Egypt for jewellery and later to make ultramarine pigment. In the eighth century, Chinese artists used cobalt blue for porcelain. In the Middle Ages, European artists used blue in cathedral windows. Europeans wore woad-dyed clothing until indigo from America replaced it. In the 19th century, synthetic blue dyes replaced organic dyes and mineral pigments. Dark blue became common for military uniforms and later for business suits. Blue was chosen for the flags of the United Nations and the European Union due to its association with harmony.

Reader's Guide

In traditional colour theory, blue is a primary colour (with red and yellow). On the HSV colour wheel, its complement is yellow; on the RYB colour wheel, its complement is orange. Blue varies in shade and tint: darker shades include ultramarine, cobalt blue, navy blue, and Prussian blue; lighter tints include sky blue, azure, and Egyptian blue. Many blue phenomena in nature arise from structural colouration, not pigments.

Did You Know?

• The modern English word 'blue' comes from Old French, of Germanic origin, related to Old High German word meaning 'shimmering, lustrous'.
• In Russian, Mongolian, Irish, and some other languages, there are separate words for light blue and dark blue.
• Several languages, including Japanese and Lakota Sioux, use the same word for blue and green.
• Linguistic research indicates that languages typically add a word for blue only after black, white, and red, often as the last main colour category.
• Isaac Newton included blue as one of seven colours in his visible spectrum, also including indigo between blue and violet.