toStringメソッドを使ったカラーコード生成

function Color (r, g, b) {
    this.r = r;
    this.g = g;
    this.b = b;
}

Color.prototype.toString = function () {
     return "#"+((((0<<8)+this.r<<8)+this.g<<8)+this.b).toString(16);
};


var red = new Color(255, 0, 0);
console.log(red); //-> #ff0000

var blue = new Color(0, 0, 255);
console.log(blue); //-> #0000ff

var cadetblue = new Color(95, 158, 160);
console.log(cadetblue); //->#5f9ea0