The task is pretty easy:
Follow the instructions described on
[url removed, login to view]!/guide/theming
and compile a green ExtJS theme. (Only change the color definition - you don't have to modify the default images.)
Deliver us the ExtJS project ( - this may be any simple example app, you do not have to write any code) and a zip of the ruby directory, so we can recompile your theme in case we change the template later ourselves.
Please use version ExtJS [url removed, login to view] on a Windows OS (for compiling).