Yeah no red dust by the capsThe red on the ears of the shaft wouldn't be of concern. If you see similar looking dust around the joint cap seal on the joint body that's a tell tale the joint is wasted. Ill usually move the wheel back and forth faster to look for play. I do the same when checking the steering components. Instead of a slow lock to lock, I will just turn the wheel between 10 o clock and 2 o'clock and look for movement.