Capturing a color!
This is actually one of the best tools available when you are working on a website. The best way of selecting colors on a website is with the hexadecimal color codes. It is hard to get exactly what you want with that though. The application that makes this a whole lot easier is called DigitalColor Meter and is included with Mac OS X. What it does is it easily lets you capture a color from anything that is on your screen. It will also show you a zoomed view that will really let you select the right pixel that you want. It will then display the hexadecimal code that you can use when coding HTML. There are many options other than hexadecimal if you are looking for something else. This great application is actually buried in the Utilities folder.