code: function tweenColors(from, to, pos) {
  		var i = 4,
  			rgba = [];
  
  		while (i--) {
  			rgba[i] = Math.round(
  				to.rgba[i] + (from.rgba[i] - to.rgba[i]) * (1 - pos)
  			);
  		}
  		return 'rgba(' + rgba.join(',') + ')';
  	}
docs: /*
  Return an intermediate color between two colors, according to pos where 0
  is the from color and 1 is the to color