toHex.js

    this.toHex = function () {
        function RGBtoHex(a) {
            function decimalToHex(d) {
                var ret = d.toString(16).split('.')[0];

                if( ret.length < 2 ) {
                    return 0 + ret
                }

                return ret.slice(0, 2);
            }

            return decimalToHex(a[0]) + decimalToHex(a[1]) + decimalToHex(a[2]);
        }

        return '#' + RGBtoHex([this.r, this.g, this.b]);
    }