 grays, string for colors
 * @param {Map} $map - the color map to use
 *
 */
/**
 * Calculates the sRGB luma of a colour
 * @private
 *
 * @param {*} $c - Color value
 *
 * https://lnikki.la/articles/sass-better-colour-based-on-brightness/
 * http://robots.thoughtbot.com/closer-look-color-lightness
 *
 */
/**
 * Style
 * Cosmetic styling settings
 *
 */
/**
 * Return a greyscale color based on $context--greyscale-base
 *
 * @param {Integer} $val - lightness value between $context--greyscale-min and $context