function rgb2hex(rgb) {
    rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
    function hex(x) {
        return ("0" + parseInt(x).toString(16)).slice(-2);
    }
    hexcolor = hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);;
    return "#" + hexcolor.toUpperCase();
}