The following terms are some of the common ones used in relation to colour chemistry and its applications.

A

Achromatic

colours resemble only black and white (grey).

Acidochromism

is a colour change, shift in absorption band and intensity, brought about by a change in pH (acidochromic).

Additive Colour Mixing

used with light, the primary colours being red, green and blue.

After-glow

occurs where a luminescent material continues to emit light long after excitation.

After-image

in a complementary hue is seen after prolonged viewing of an intensely coloured object.

Anodoluminescence

is radioluminescence caused by ?-particles.

B

Bathochromic

when an absorption band moves towards longer wavelengths (also called a red-shift).

Bioluminescence

is the production of light by living systems.

C

Candololuminescence

is the luminescence in incandescent solids.

Cathodoluminescence

is the luminescence observed upon excitation by high-energy electrons.

Chemiluminescence

is the production of light by chemical substances without the help from other energy sources; in effect it is the conversion of energy stored in chemical bonds into light.

Cholesteric

the liquid crystal phase formed by molecules with a chiral centre (also called the chiral nematic phase).

Chroma

is the attribute of a colour that expresses the degree by which it differs from an achromatic colour of the same lightness.

Chromatic

colours possessing a hue (do not resemble grey).

Chromaticity coordinates

are two numbers (denoted x and y) which together represent in the CIE system the colour quality.

Chromaticity diagram

is a diagram which shows the colour...