Purple is any of a group of colors intermediate between blue and red.

On a chromaticity diagram, the straight line connecting the extreme spectral colors (red and violet) is known as the line of purples (or purple boundary); it represents one limit of human color perception. The color magenta used in the CMYK printing process is on the line of purples, but most people associate the term "purple" with a somewhat bluer shade. There is some common confusion between the color names purple and violet.

In the 1800's William Perkins invented mauve, a shade of purple, from coal oil. It quickly became popular among all classes, and sparked major industrial development in the German chemical industry.