I think I looks good and that's all that matters... Right?

Pleasant Green, material feel

Pro: the pastel colors make text and icons more visible and easier to read than the FF default theme.

Con: in MS Windows, at least, when the FF title bar is active, this theme does not change the color of the title bar to indicate when the browser window has lost focus.

Very nice shades

Very pretty, adds color without being distractive or making fonts, links, etc difficult to read.