When I build a site I tend to do a bit of graphic design (developer style) in Paint.NET, but how do I know the colors will all display properly on all browsers on different machines? What color depth to you generally code for? 16bit 256 colors etc.
I don't worry about whether the colors will display perfectly everywhere, as even the most basic of cell phones support 16-bit color.
In my opinion, the days of having to worry about 'web-safe' colors is mostly over.
As long as you're not using colors incredibly similar to each other, you should be good.