Right at the beginning of the final hand-to-hand combat above the mountain crevasse, the Machredsch loses his red Turkish cap. In the close-up shots he is seen bare headed then. However, during most of the wide shots he is still wearing his red cap, up to the end of the fight.
When Lord Lindsay and Archibald are rolling down the hill falling right into the hands of Abu Seif he looses his top hat when they stop on the ground. There you see a black haired stuntman standing in for original Lord Lindsay Dieter Borsche. In the next close-up scene Lord Lindsay is again gray-haired.