Dichromic

Dichromic is an adjective describing something that has two colors or can display two colors. The term comes from Greek di- meaning two and chroma meaning color, and it is used across disciplines to denote dual chromatic properties rather than a single, fixed hue.

In optics and materials science, dichromic (often used interchangeably with “dichroic”) materials alter their appearance with the light path or polarization. A dichroic filter transmits one color while absorbing others, and dichroic glasses or pigments can appear to shift hue when viewed from different angles or under different lighting. This behavior arises from anisotropic absorption of light in the material.

In crystallography and mineralogy, dichroic or pleochroic crystals show different colors when observed along different crystallographic axes, a consequence of direction-dependent light absorption. The term dichromic is sometimes used in casual language to describe such dual-color behavior, though more precise terminology in science often favors pleochroic or dichroic.

In color science and related fields, dichromic may appear in reference to two-color patterns in biology, art, or design where an object or composition presents two dominant colors. In historical color-vision literature, dichromic has been used to describe organisms or perceptual states associated with two-color vision, though modern terminology typically uses dichromatic or dichromacy to describe two-cone color perception.