Looks like this Firefox theme is feeling a little blue. The Blu Canidae theme for Firefox is a modified version of the iFox theme with Photoshop CS3 style icons. The combination of those great features makes for a really nice looking blue/mac-ish theme.
Here is a little more about the theme from the developer:
This was designed to be a cleaner, blue version of iFox. It has stylized buttons, and is intended to be a new alteration of my old theme, Blu Vos. I hope you like it. If you can, please leave a comment and a review. This helps me out immensely. If you run into any problems, or find any flaws, please tell me! I want to make this theme better, and your assistance makes that possible.
You can pickup the Clu Canidae theme yourself on the Firefox Add-ons web site.