Problem
The problem with this image is the close proximity of the dark and highlighted hair against a gray background color that shares the same tonal qualities. Trying to mask both shades of hair under these circumstances should be very problematic and only possible with a lot of manual intervention.
Solution
Using Fluid Mask 3's new and vastly improved hair blending patches we were able to achieve the seemingly impossible! Within five minutes we created a perfect cut-out of the light and dark hair using the hair blending algorithms available in the Patch Properties (Blending Tab). Who needs a green screen when you've got Fluid Mask 3? (the funny thing is that we have gone from gray to green screen here!)