I can already complaiine that none of the tools for live CSS editing, support SASS or LESS (or other pre processor).
But they speed up your life so much we cannot complaine longer.
FireBug plug in http://www.cssupdater.com/
Prerequisites: Adobe Air, Firefox and minumum FireBug
Style Editor 1.0
Requirements: Firefox 12.0 and later
Ma con Firefox 25.0 non compare il menu in right click
What a waste Filezilla Colorpicker it copy just the color hexe code that are wrote in the css code
Not only the best colorpicker on add ons market but also a precious tool for gradient generator!
Colorzilla pick also the value color from images, jpg… converting in webstandard Hex format.
If I can say something the only bad thing will be to have another standalone on the tollbar of my browser.