History of Blue in Timeline

Blue is a primary color in both the RGB and RYB color models, situated on the visible light spectrum between violet and cyan, typically associated with wavelengths between 450 and 495 nanometers. It's observed in the daytime sky and deep sea due to Rayleigh scattering. The Tyndall effect explains blue eyes, while aerial perspective causes distant objects to appear more blue.

1900: Lapis Lazuli Value in the Indus Valley Civilisation

Around 1900 BC, Lapis lazuli was highly valued by the Indus Valley Civilisation.

1900: Blue eyes in America

Around 1900, about half of Americans were born with blue eyes.

1902: US Army uniform color until 1902

Blue continued to be the colour of the field uniform of the US Army until 1902, and is still the colour of the dress uniform.

1911: Einstein confirms Rayleigh scattering

In 1911, Albert Einstein confirmed Rayleigh scattering. Rayleigh scattering describes how sunlight passes through the atmosphere, where the blue wavelengths are scattered more widely by the oxygen and nitrogen molecules, resulting in more blue light reaching our eyes.

1950: Blue eyes in America

Around 1950, a third of Americans were born with blue eyes.

1978: Eye color distribution in Denmark

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

1993: Demonstration of high-brightness blue LEDs

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 LED lighting development.

2006: Nakamura awarded Millennium Technology Prize

In 2006, Nakamura was awarded the Millennium Technology Prize for his invention.

2006: Blue eye statistics 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.