Mirage III RS "AMIR" helmet.
Its PRU-36 visor cover was modified in order to not interfere with the initiating handle of the Mirage's Martin Baker ejection seat.
Those helmets were painted with the same camouflage colours as the aircraft.
For the type of mission they performed, the Mirage III RS flew at very low altitude. For a higher flying one, a white helmet may have been the most visible part of a lower flying camouflaged airplane.
Note the black MBU/5 oxygen mask shell.
Note: the above degraded image is taken from the book “L’histoire des Mirage Suisses” by Laurent Baudillon, for educational purposes only in accordance with the Berne Convention, Art. 10.