Converting integers to hex string in JavaScript

To convert a number to hex, you can use the built-in toString(16) function. Simple code:

function convert(integer) {
    var str = Number(integer).toString(16);
    return str.length == 1 ? "0" + str : str;
};

function to_rgb(r, g, b) { return "#" + convert(r) + convert(g) + convert(b); }

var color = to_rgb(r, g, b);

Just use the RGB values, like:

this.context.fillStyle = "rgb(0,255,255)";