Here is the link to the website: www.taaz.com
As with www.thehairstyler.com, the visualization tools aren't perfect, but as you can see in the examples below, you can definitely get general ideas about how various colors work (or don't work) with your personal look. Whether you are just learning how to optimize your look, or want to revisit it, this website can be an invaluable tool. (And don't be so sure that you already know everything about your own makeup - self-perception is remarkably inaccurate at times.)
1. How to Avoid Looking "Fake"
2. How to Improve Your Hair
3. Your Skin Color Matters
4. Hair and Makeup Variety