Undo / adjust earlier changes

[Vera23]

Hi all, 

Recently I started editing and I'm trying to learn GIMP. Now I have a question I'm hoping you could help me with. 

When I change something in e.g. colour balance and press ok, the next time I open it, everything is back to zero, while the picture is clearly edited. So I can't reset or adjust stuff, except for using ctrl Z, or using the undo history. If I use the undo history however, all the changes I made past the colour balance are also undone. Is there any way to fix this?

Thank you in advance!

[rich2005]

As you found, you cannot selectively edit the Gimp 'undo' stack only go back to a specific point. The undo stack is not retained when you save then exit Gimp.

Do not rely on 'undo'. Adjust your work flow.
Save versions (name01.xcf , name02.xcf ...etc) as you go along
or
Create stages in your editing. You made some color balance adjustment. Use Layer -> `New from Visible' and continue.
Under that Layer is previous, above is new editing based on new-from-visible. Repeat as required.

[denzjos]

When I work on photos or pictures, I always make a copy of the original photo or picture to a new layer and work on the copy. As Rich mentioned, save the stages of your work as different names (001, 002, 003....)

[Vera23]

Thank you both for your quick reply and suggestions!