I believe your tool is very useful for choosing color patterns

I have used Mr. Roundy´s tool for years. However his annoying "Don´t leave my site" promo has caused me to bookmark yours instead. :)

I think that the practice of using "web-safe colors" is archaic and limiting. The vast majority of users´ graphics systems these days have millions of colors. The one notable exception would be smart phones, but typically a web designer will create pages just for them.

Further, a poorly calibrated monitor will shift ALL the colors, and if your site is made up of colors that go together, chances are the shifted colors will too. Not to mention the fact that that user is used to looking at every site on the ´net with skewed colors. If your web site looks nice with proper colors, it won´t look that bad in comparison to other sites out there.

Any potential drawback of not using web-safe colors is just not worth the penalty of having an ugly site.