I took a Munsell Color Wheel that I found on the internet and used Photoshop to tweak it slightly so that I could put a mask over it to play around with gamut masking.
Be sure and check out James Gurney’s blog about gamut masking along with video
Gurney Gamut Masking Part 1
Also painter Richard Robinson has created a wonderful, totally interactive gamut masking tool that you can find (and use) on the internet, be sure and check that out as well.
Gamet Masking Tool