One of the pains dealing with CSS is when debugging a large set of styles and then wondering what the viewable color is for the HEX or RGB value you have highlighted/selected. Most of the time it is in HEX format and I have to use another 3rd party application or online website to convert the value to an actual viewable color. Then I can (hopefully) find where the class was used in the page I'm looking at.

Another problem is when adding a color using the color tool button (on the Tools toolbar) does not allow me to enter a HEX value to see what it looks like. Only RGB and HUE settings are available and that's like 5% of the different styles I have to figure out on average. The color tool needs to be fleshed out a bit more to include some advanced features. Refer to a real nice online color application: