Adobe has recently launched a colour scheme designer. This is useful for web designers as it is easy to play around with colour combinations that work well together. There is a gallery of other peoples creations which you can choose from. The downloadable colour schemes only work with Photoshop CS2 or above. You can use the apple colour picker within Photoshop Elements to lift the colours from the screen. If you want the colours to customise website css files you can simply take a note of the hex values when in create mode.
http://kuler.adobe.com/