I was flying with China Airlines out of Taipei and noticed that on some baggage trolley trucks, the rear rim is a grayish color. Is this the desired look or is something not loading properly. This very well just be the desired look as everything else is working normally, but I would like to confirm that it is or not (photo on link provided)
https://drive.google.com/file/d/1ma5pZ_UDJpn5EphqoSfJcBuwoO4nus9X/view?usp=drivesdk