Javascript color scale from 0% to 100%, rendering it from red to yellow to green

// License: MIT - https://opensource.org/licenses/MIT
// Author: Michele Locati <[email protected]>
// Source: https://gist.github.com/mlocati/7210513
function perc2color(perc) {
    var r, g, b = 0;
    if(perc < 50) {
        r = 255;
        g = Math.round(5.1 * perc);
    }
    else {
        g = 255;
        r = Math.round(510 - 5.10 * perc);
    }
    var h = r * 0x10000 + g * 0x100 + b * 0x1;
    return '#' + ('000000' + h.toString(16)).slice(-6);
}