Yeah and I tried to mess with those without much success. I don't quite understand why Geralt's hair is barely affected by reduction of camera light. With reduced camera light, his skin becomes significantly darker, but his hair stays almost the same. There should be some shader or mesh properties that adjust the degree to which that mesh is affected by the environment, similar to parameters in HW redfur files.
Then there is some discrepancy between normal beard and normal hair in color (no HairWorks involved).