Converts a color name to its corresponding hex string.

getColorNameFromHexColor.js

/**
 * Converts a color name to its corresponding hex string.
 * 
 * @example getHexColor('orange') == '#ffa500'
 * @param {String} colorValue The color name.
 * @return {String}
 */
var getColorNameFromHexColor = (function() {
    var elem = document.createElement('div');
    var bg;
    
    function hex(x) {
        return ('0' + parseInt(x).toString(16)).slice(-2);
    }
    
    return function(colorValue) {
        elem.style.backgroundColor = colorValue;
        
        if (elem.currentStyle) {
            bg = elem.currentStyle["backgroundColor"];
        } else if (window.getComputedStyle) {
            bg = document.defaultView.getComputedStyle(elem, null).getPropertyValue("background-color");
        }
        
        if (parseInt(bg.search('rgb'), 10) === -1) {
            return bg;
        } else {
            bg = bg.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
            
            return '#' + hex(bg[1]) + hex(bg[2]) + hex(bg[3]);
        }
    };
})();