This is a dark theme that you can use to make your ChatZilla IRC client look spiffy. All you need to do is just checkout the code (from Google Code) into your
c:\Program Files\ChatZilla directory using hg (or, alternatively you can download and extract the code). Then in ChatZilla, edit your
Global Settings -> Appearance -> Dark Motif and browse for your checked out code. Then
View -> Color Scheme -> Dark to apply.
You can follow these same instructions (minus the downloading) to try it out first by putting (not browsing)
http://jelly-bean-dark-theme-for-chatzilla.googlecode.com/hg/chatzilla.css in the dark motif section in your Global Settings.
[Jelly Bean Dark Theme for ChatZilla…] @Google Code