Since fvwm is a wm, it doesn’t care about the theme/icons used in gtk apps. Is there a way to “load” those? I know one way to do it is run ‘gnome-settings-manager’, but it’s doing more than what I want. Specifically, it draw a wallpaper, but I only care for decoration of application controls and icons. The same question can be asked about qt apps, of course.
Write your own ~/.gtkrc-2.0 file.
– Thomas Adam
LXAppearance is a nice app. for changing the appearance of the gtk theme.