docs: function rgbToHex(r, g, b) {
    var integer = ((Math.round(r) & 0xFF) << 16)
      + ((Math.round(g) & 0xFF) << 8)
      + (Math.round(b) & 0xFF);
  
    var string = integer.toString(16).toUpperCase();
    return '#' + ('000000'.substring(string.length) + string);
  }