21st Century Blue

21st century

The 21st century is the current century in the Anno Domini or Common Era, in accordance with the Gregorian calendar. It began on 1 January 2001, and will end on 31 December 2100. It is the first century of the 3rd millennium.

Century

A century is a numerical value of 100 or more popularly period of 100 years. Centuries are numbered ordinally in English and many other languages. The word century comes from the Latin centum, meaning one hundred. Century is sometimes abbreviated as c. currently the 21st century is ongoing, started on first January 2000.

Blue

Blue is one of the three primary colours in the RGB (additive) colour model, as well as in the RYB colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colours perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.

21st

Adjective

1. Abbreviation of twenty-first.

century

Noun

1. A period of one hundred consecutive years; often specifically a numbered period with conventional start and end dates, e.g., the twentieth century, which stretches from (strictly) 1901 through 2000, or (informally) 1900 through 1999. The first century AD was from 1 to 100.
2. A unit in ancient Roman army, originally of one hundred army soldiers as part of a cohort, later of more varied sizes (but typically containing sixty to seventy or eighty) soldiers or other men (guards, police, firemen), commanded by a centurion.

blue

Adjective

1. Of a blue hue.
2. Depressed, melancholic, sad.

Noun

1. The colour of the clear sky or the deep sea; the colour midway between green and violet in the visible spectrum and one of the primary additive colours.
2. Anything coloured blue, especially to distinguish it from similar objects differing only in colour.