First of all, if you are still using Internet Explorer you should dump it as soon as possible. Some of the reasons to go with Firefox include: security, tabbed navigation, customization and the possibility to add useful extensions.
There are many of those extensions, in fact, that are very handy for bloggers. ColorZilla is an extension that allows you to discover the color of any website by simply moving your mouse over it. You can also zoom pages, measure the distance between two points, export colors’ code and much more.
If you creating a new blog or thinking about redesigning an existing one you should definitely try this extension out.