customising GTK+ for pidgin...

I tend to try to keep my systems mostly consistant in terms of look and feel - i tend to use wonton soup or obsidian coast on KDE. I use slate with the tint all the way to max on windows 7 - but GTK apps tend to be designed around XP, and look out of place. The 'closest' stock theme seems to be aurora midnight, and you can do minor tweaks with the gtk plugin.

for major tweaks, use the gtk plugin to find the colour (or take a screenshot, and the colour picker tool in PDN), and edit the gtkrc file manually.
use notepad++ or some other unix-ending aware tool.