Actor Christian Bale wears Ray-Ban 3324 sunglasses in the 2008 Batman movie The Dark Knight. The exact color of the Ray-Ban sunglasses that Christian Bale is wearing is Gunmetal frame and Green Polarized lenses, color-code 004/58.
The glasses are available with normal lenses and Polarized lenses. The Polarized version is usually around $40 more expensive than the normal one.
Reference: Ray-Ban RB 3324 - Color: Gunmetal frame, Chrystal Green Polarized lenses (code 004/58)