History of Blue in Timeline

Blue is a primary color in both the RYB and RGB color models, situated on the visible light spectrum between violet and cyan, typically associated with wavelengths from 450 to 495 nanometers. Variations like azure and ultramarine contain admixtures of green and violet, respectively. The blue appearance of the sky and sea is attributed to Rayleigh scattering, while blue eyes result from the Tyndall effect. Aerial perspective explains the bluish hue of distant objects.

1900: Blue eyes in the United States

Approximately half of Americans born in 1900 had blue eyes.

1900: End of Indus Valley Civilization

The Indus Valley Civilization, which highly valued lapis lazuli, ended around 1900 BC.

1902: End of Blue Field Uniform for US Army

In 1902, the US Army discontinued the use of blue as the color of the field uniform, though it remains the color of the dress uniform.

1911: Rayleigh Scattering Confirmed

In 1911, Albert Einstein confirmed Lord Rayleigh's theory on Rayleigh scattering. This theory explains why the sky appears blue: when sunlight passes through the atmosphere, the blue wavelengths are scattered more widely by oxygen and nitrogen molecules, resulting in more blue light reaching our eyes.

1950: Blue eyes in the United States

Approximately a third of Americans born in 1950 had blue eyes.

1978: Blue eye prevalence in Denmark

In Denmark in 1978, only 8% of the population had brown eyes. However, due to immigration, that number is about 11% today.

1993: High-Brightness Blue LEDs Demonstrated

In 1993, Shuji Nakamura of Nichia Corporation demonstrated high-brightness blue LEDs. Simultaneously, Isamu Akasaki and Hiroshi Amano of Nagoya University were working on related developments that revolutionized LED lighting.

2006: Nakamura Awarded Millennium Technology Prize

In 2006, Shuji Nakamura was awarded the Millennium Technology Prize for his invention of the blue LED.

2006: Blue eyes in the United States

In the United States, as of 2006, 1 out of every 6 people, or 16.6% of the total population, and 22.3% of the white population, have blue eyes.

2010: Widespread Availability of Blue Lasers

In 2010, lasers emitting in the blue region of the spectrum became widely available to the public with the release of inexpensive high-powered 445–447 nm laser diode technology.