Performance metrics & physics
Albedo
Albedo is the proportion of solar radiation reflected by a surface; a black car body has very low albedo (absorbing most sun), while a white car has high albedo.
Albedo varies from near 0 (perfect absorber) to 1 (perfect reflector). Pure white surfaces approach 0.8; black absorbs almost everything.
For automotive thermal performance, vehicle colour affects body and cabin heating. Black cars heat up faster than white ones in the same conditions.
Window film doesn't change a car's albedo from outside, but it changes the effective interior albedo by reflecting solar energy at the glass.