polychromatic

Polychromatic is an adjective describing objects or phenomena that display many colors. The term derives from the Greek poly- meaning “many” and chroma meaning “color.” It is often contrasted with monochromatic, which refers to a single color or wavelength.

In science, polychromatic describes light that contains a spectrum of wavelengths. Sunlight is the most familiar example of polychromatic light, and such light can be dispersed into a rainbow by a prism. By contrast, monochromatic light consists of a nearly single wavelength, such as light from many lasers.

In art and cultural history, polychromy refers to the practice of applying multiple colors to sculptures, architecture, and other works. Polychrome or polychromy is common in many ancient civilizations, where colored surfaces were later erased or covered by later restoration or preservation efforts. The term also describes works that employ a diverse color palette.

In mathematics and computer science, polychromatic colorings are colorings in which each structural unit, such as a hyperedge, contains all colors in use. The polychromatic number of a system is the greatest number of colors for which such a coloring exists. This concept appears in combinatorics and related fields and has variants for graphs, hypergraphs, and other combinatorial structures.

Related concepts include polychromatic imaging, which combines data from multiple wavelengths for analysis or display, and polychrome, a noun referring to a multicolored object or artwork.