JS object

function robot(headcolor, armcolor, legcolor, bodycolor) {
    this.headcolor = headcolor;
    this.armcolor = armcolor;
    this.legcolor = legcolor;
    this.bodycolor = bodycolor; 
}

var color = {
    head: "#ADD8E6",
    body: "#ADD8E6",
    legs: "#ADD8E6",
    arms: "#ADD8E6",
    getColor: function (head, body, arms, legs) {
        this.head = head;
        this.arms = arms;
        this.legs = legs;
        this.body = body;
    }
};

function drawRobot(color) {

    // head
    ctx.fillStyle = color.head;
    ctx.fillRect(100, 0, 110, 70);

    // body
    ctx.fillStyle = color.body;
    ctx.fillRect(125, 70, 60, 90);

    // legs
    ctx.fillStyle = color.legs;
    ctx.fillRect(125, 160, 15, 40);
    ctx.fillRect(170, 160, 15, 40);

    //arms
    ctx.fillStyle = color.arms;
    ctx.fillRect(75, 85, 50, 8);
    ctx.fillRect(185, 85, 50, 8);

    // Eyes
    ctx.beginPath();
    ctx.arc(130, 30, 10, 0, 2 * Math.PI);
    ctx.stroke();

    ctx.beginPath();
    ctx.arc(170, 30, 10, 0, 2 * Math.PI);
    ctx.stroke();

}

function setColors() {
    color.getColor(document.colors.head.value, document.colors.body.value,
        document.colors.arm.value, document.colors.leg.value);
    drawRobot(color);
  
}

var btn = document.createElement("BUTTON");
btn.onclick = setColors;
document.body.appendChild(btn).appendChild(document.createTextNode("Set Colors"));
var c = document.createElement("CANVAS");
c.width = 300;
c.height = 300;
document.body.appendChild(c);
var ctx = c.getContext("2d");

drawRobot(color);