Although on some photos the frame looks black, he is wearing tortoise colored Wayfarers in the film. On a close-up photo (see this website) the tortoise frame can clearly be seen. He may have worn a black frame version as well on set, see for example here.
The Ray-Ban Wayfarer sunglasses are one of the most popular sunglasses ever made and can be seen on many celebrities, see our overview of Ray-Ban Wayfarer sunglasses.
Reference: Ray-Ban Wayfarer - Color: Havana (tortoise) frame color code 902