Metamerism has at least three meanings:

• Metamerism (biology) is the property of having repeated segments, as in annelids; a concern of zoology and developmental biology
• The chemical property of having the same proportion of atomic components in different arrangements (obsolete, replaced with isomer)
• Metamerism (color), relates to two colors and their relation under different light sources. It also defines the capability of humans to recognise different colours and their relation under different light colours (sun, bulb, neon,...)