Add an option to load presets for Firefox settings. I have poor eye site. In order to read the text I am writing I have the zoom set to 170. Add to that the size and color of the icons it is difficult to tell what the icons represent. by a preset I mean when first installed give options to set toolbar height and width, select the color used or simply select black and white. Colors are pretty and icons look cool but are useless until you know what they represent.

 This support page is black and white. Other than the fact that many of your users will need to set a high zoom it looks pretty good.