Source: src/ol/color/color.jsdoc

/**
 * Colors can be defined as a {@link ol.Color} array, or as strings in
 * `rgb(r,g,b)` or `rgba(r,g,b,a)` format, or in hex `#rrggbb` or `#rgb` format.
 * Color names, like 'red', 'blue' or 'green', may also be used with the
 * Canvas renderer.
 *
 * @namespace ol.color
 */