[Gimp-user] ANSWER: Fix invisible tooltip in Gimp, Inkscape for Windows High Contrast Black theme

[Innominate_Null <forums gimpusers com>]

Fix invisible tooltip text with Windows High Contrast Black system theme
(Inversed, white text on black background)

Includes references to Inkscape as well since the same steps can be used foe it
as well.

Using Win 8.1 with
Gimp 2.8.18
Inkscape 0.92.4
no 3rd party theme, relying on Gimp/Inkscape applying system theme

I had this issue for many versions of software that uses gtk.  You don't want to
know how much time I have used  Gimp & Inkscape without tooltips.  Using Windows
High Contrast Black can be a real headache.

What worked for me:

1) Close Gimp/Inkscape.

2) With File Explorer, go to C: > Users > (user name) > .gimp-2.8 > themes >
MS-Windows > gtk-2.0

a) If Gimp is installed on another drive, the location to go towould be like
this-- D:> Program Files > GIMP 2 > share >themes >MS-Windows > gtk-2.0

(for Inkscape-- go to C: > Program Files > Inkscape > Share > Themes >
MS-Windows > gtk-2.0 (if Inkscape is installed on the C Drive, it's the same
path if its on another drive though)}

3) In that folder, there's a file named “gtkrc”, rename it (F2 key) to
“gtkrcoriginal”.  a pop up warning will ask if you are sure, tell it "to make it
so"

4) Right click on "gtkrcoriginal”, choose "Open with" and from the programs
listed, choose "Notepad"

5) With the "gtkrcoriginal" file open in Notepad (or other text editor), paste
the following at the end of the file:

###########################################################

style "hiconinverse-tooltips-style" = "gimp-dark-default-style"
{
  xthickness = 7
  ythickness = 4

  bg[NORMAL] = "#000000"   #ffffff original value
  bg[SELECTED] = "#000000"   #unknown function not changed
  fg[NORMAL] =  "#ffffff"   #000000 original value
}

widget "gtk-tooltip*" style "hiconinverse-tooltips-style"

###############################################################

6) CRITICAL PART: tell Notepad  (or other text editor) to save the file using
the SAVE AS command and save the file as "gtkrc” (not "gtkrcoriginal" don't
include the double quote marks).  If your text editor insists upon adding ".txt"
to the filename, no worries-- see next step.  Also make sure its saving the file
to the folder it came from (the C: > Users > (user name) > .gimp-2.8 > themes >
MS-Windows > gtk-2.0 folder).

(for Inkscape-- the Inkscape > Share > Themes > MS-Windows > gtk-2.0 folder)

7) Close Notepad and go back to File Explorer, it should be still at C: > Users
> (user name) > .gimp-2.8 > themes > MS-Windows > gtk-2.0.  If "gtkrc” is named
"gtk.txt", rename it (using F2 key) to “gtkrc".  The pop up warning will again
ask if you are sure, tell it "to make it so".

8) Close File Explorer and start Gimp/Inkscape and you should have white text on
black backgrounds.


TROUBLESHOOTING:

A) If you make a mistake with Step (6) saving your edited file 

1) didn't change the file name to gtkrc but overwrote gtkrcoriginal

a) Gimp will start but will have default white theme, Windows system theme won't
be applied.
b) Reopen gtkrcoriginal, delete delete the edited gtkrc and rename gtkrcoriginal
to gtkrc or delete the section you pasted into the gtkrc file in Step (5) and
save file.
c) and using the gtkrcoriginal file you have open in a text editor, repeat Step
6's instruction-- save the file using the SAVE AS command and save the file as
"gtkrc” (not "gtkrcoriginal" don't include the double quote marks). Follow the
rest of Step 6, 7 & 8 again.


2) If things don't work as advertised or you wish to return to the default Gimp
gtkrc, you can simply delete the edited gtkrc and rename gtkrcoriginal to gtkrc
or delete the section you pasted into the gtkrc file in Step (5).

a) if you change Windows system theme at a future date, you will probably need
to remove this fix and restore the to the default Gimp gtkrc so it doesn't
interfere with the new system theme.

-- 
Innominate_Null (via www.gimpusers.com/forums)