Blue is one of the three primary colours of pigments in painting and traditional colour theory, as well as in the RGB colour model. It lies between violet and green on the spectrum of visible light.
Bluetooth is a wireless technology standard for exchanging data between fixed and mobile devices over short distances using short-wavelength UHF radio waves in the industrial, scientific and medical radio bands, from 2.400 to 2.485 GHz, and building personal area networks . It was originally conceived as a wireless alternative to RS-232 data cables.
Blues is a music genre and musical form which was originated in the Deep South of the United States around the 1870s by African Americans from roots in African musical traditions, African-American work songs, spirituals, and the folk music of white Americans of European heritage. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads.
The blue whale is a marine mammal belonging to the baleen whale parvorder, Mysticeti. At up to 29.9 metres (98 ft) in length and with a maximum recorded weight of 173 tonnes (190 short tons), it is the largest animal known to have ever existed.Long and slender, the blue whale's body can be various shades of bluish-grey dorsally and somewhat lighter underneath.