I don't like how Firefox looks with the default theme. It's good that the theme can be changed on the portable version too!
The best looking theme I found is Qute mod.
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There's no point in this post - you're not asking for anything, and you're not really saying anything much either.
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Get the Firefox extension Colors. Restart it once and choose from its themes (no restart required to change its themes). Restart Firefox again and it can now use Firefox Personas. It doesn't change the theme, per se, but the CSS, I suppose, which draws it. Most change the background image and/or text color. But with that and some toolbar tweaking, my Firefox looks great. (This is the Persona I'm using BTW.)