Created attachment 12145 [details]
Classic-test.tgz, to demo the problem with Gimp 1.3

I don't know what the GIMP does with icon themes. Might be
a bug there. Icon themes have gotten a fair bit of testing
for accessibility stuff, and seem to work pretty well
with GTK+-2.2.

What is the point you are trying to proove here? As far as I can see
your theme is working correctly. I get the prefs dialog w/o icons and
I get a relief in the toolbox.

The rest of your gtkrc looks pretty much b0rken and I don't get what
exactly you are trying to achieve here. It seems we need to distribute
a theme with The GIMP so you have something to copy from. Actually I
was hoping we could use your theme for this purpose :-(

The point was (here it still is), that the navigation "four
arrows" image should appear as a green square in the image
windows, but appears as blue, which is the image for all the
other sizes. Forget about reliefs or preference windows, just
track where gimp navigation icons appear.

Using GLE as inspector, it shows all is OK. If you force the
size with GLE to a different value, and change back to the
original one, the green square appears. In other places, like
a tab header for navigation preview (dock), the green version
appears since the first time it is draw, as it should.

So the line '{ "images/test-green.png", *, *, "gtk-button" },'
that appears in the file 'gtkrc-icons' is only in effect in the
image window after GLE forcing it by the change. If all would be working, it should be green for size 4 (button size) as soon as
it is draw on screen, without GLE tricks.

The GLE steps I used: gimp-1.3 --gtk-module=gle, Ctrl+Alt+Tab to
get GLE on screen, click Selector and click in an image window.
MB3 click in image_window entry and choose Tree Editor. Then
via MB3 again choose Object editor for GimpDisplayShell - GtkVBox
- GtkVBox - GtkHBox - GtkEvenBox - GtkImage. You get a window
where it says Icon size 4 and Stock ID gimp-navigation. Change
size to 3 and back to 4, icon changes colour.

The point was (here it still is), that the navigation "four
arrows" image should appear as a green square in the image
windows, but appears as blue, which is the image for all the
other sizes. Forget about reliefs or preference windows, just
track where gimp navigation icons appear.

Using GLE as inspector, it shows all is OK. If you force the
size with GLE to a different value, and change back to the
original one, the green square appears. In other places, like
a tab header for navigation preview (dock), the green version
appears since the first time it is draw, as it should.

So the line '{ "images/test-green.png", *, *, "gtk-button" },'
that appears in the file 'gtkrc-icons' is only in effect in the
image window after GLE forcing it by the change. If all would be
working, it should be green for size 4 (button size) as soon as
it is draw on screen, without GLE tricks.

The GLE steps I used: gimp-1.3 --gtk-module=gle, Ctrl+Alt+Tab to
get GLE on screen, click Selector and click in an image window.
MB3 click in image_window entry and choose Tree Editor. Then
via MB3 again choose Object editor for GimpDisplayShell - GtkVBox
- GtkVBox - GtkHBox - GtkEvenBox - GtkImage. You get a window
where it says Icon size 4 and Stock ID gimp-navigation. Change
size to 3 and back to 4, icon changes colour.

No idea what is really going with the blue icon and no
time. Anybody that gets weird icons can open new bugs.