Cool, I got pointed to this app:
Adobe Consulting | User Experience Hub: New Flex Style Explorer: Jam-Packed with New Features
It can run in browser from the adobe site, or you can download it to run it offline. This app allows you to edit the CSS attributes directly, with a great GUI; I'm extremely impressed with how easy this app is to use.
This works on all platforms. This tool is amazing for web developpers and webdesigners.