Tip: Loading specific gtk theme for a specific application
 

Last week, I stumpled upon this blog posting and find it worthwhile mentioning.

To change one specific application to one GTK theme, do this:

GTK2_RC_FILES=.themes/SomeTheme/gtk-2.0/gtkrc gqview

See the screenshot for two running gqviews with different themes (Anianian and Milk Mint) loaded. (Compare the scrollbars, the menu icons and the highlighting color of the file selector...)