onKeyword method
Returns a String with the background color set to the color represented by the passed in color keyword. This accepts all of the standard X11/CSS/SVG color names, and the user can extend the list of accepted color keywords using the addColorKeywordRgb() and addColorKeywordHex() methods
Implementation
String onKeyword(String colorKeyword) =>
(_chalk.onKeyword(colorKeyword))(this);