Crimson is a rich, deep red color, inclining to purple. It originally meant the color of the kermes dye produced from a scale insect, Kermes vermilio, but the name is now sometimes also used as a generic term for slightly bluish-red colors that are between red and rose. Crimson is produced using the dried bodies of a scale insect, Kermes, which were gathered commercially in Mediterranean countries, where they live on the kermes oak, and sold throughout Europe. Kermes dyes have been found in burial wrappings in Anglo-Scandinavian York. They fell out of use with the introduction of cochineal, also made from scale insects, because although the dyes were comparable in quality and color intensity, ten to twelve times as much kermes is needed to produce the same effect as cochineal.

Source: Wikipedia