This article is about the visible spectrum. For all other uses see: Spectrum (disambiguation)

The spectrum in a rainbow

A spectrum, plural: spectra, is a band of several colours: violet, indigo, blue, green, yellow, orange and red. A spectrum can be seen if the Sun's light is passed through a prism and allowed to gather on a white screen. This visible spectrum is part of the larger electromagnetic spectrum. Spectroscopy is the study of spectra.