This is what Wikipedia says about Crimson
"Crimson is a strong, bright, deep red color. It originally meant the color of the Kermes dye produced from a scale insect, Kermes vermilio, but the name is now also used as a generic term for slightly reddish-blue colors that are between red and rose; besides crimson itself, these colors include carmine, raspberry, ruddy, ruby, amaranth, and cerise. The color was very common for casual clothing in Ancient Roman culture. The Romans called the color purple."