docs: function (from, to, pos) {
  		// Check for has alpha, because rgba colors perform worse due to lack of
  		// support in WebKit.
  		var hasAlpha,
  			ret;
  
  		// Unsupported color, return to-color (#3920)
  		if (!to.rgba.length || !from.rgba.length) {
  			ret = to.raw || 'none';
  
  		// Interpolate
  		} else {
  			from = from.rgba;
  			to = to.rgba;
  			hasAlpha = (to[3] !== 1 || from[3] !== 1);
  			ret = (hasAlpha ? 'rgba(' : 'rgb(') + 
  				Math.round(to[0] + (from[0] - to[0]) * (1 - pos)) + ',' + 
  				Math.round(to[1] + (from[1] - to[1]) * (1 - pos)) + ',' + 
  				Math.round(to[2] + (from[2] - to[2]) * (1 - pos)) + 
  				(hasAlpha ? (',' + (to[3] + (from[3] - to[3]) * (1 - pos))) : '') + ')';
  		}
  		return ret;
  	}