code: function getRGBBytes(color, out) {
      out = out || [0, 0, 0];
      out[0] = Math.round(color[0]*255);
      out[1] = Math.round(color[1]*255);
      out[2] = Math.round(color[2]*255);
      return out;
  }
docs: Returns RGB color components as bytes (0..255)
  @param  {Array} color - RGBA color array [r,g,b,a]
  @param  {Array} out   - array to copy values into
  @return {Array}       - RGB color byte array [r,g,b] (0..255) or updated out array