Sample images of the color indigo are available on Depaul University's website. A strip of the color indigo, along with its correspondinghexadecimal value, is also featured at W3Schools. As of 2015, indigo is one of 140 colors supported by all web browsers.
The color indigo is one of the spectral lines produced when visible light is split into its individual components. The coloris commonly associated with the indigo dye. Depaul University provides a variety of photographs depicting the color, including building structures, lumps of indigo dye and an indigo bunting. W3Schools also presents different shades and possible mixes for the color indigo.