getting & setting colors

[Dave Howorth <dhoworth mrc-lmb cam ac uk>]

I want to temporarily change the background or foreground color in a
widget (TextBuffer or Entry), to highlight errors.

I've found gtk_widget_modify_bg, which looks like it will let me change
the background colour, but I can't see any way to return the color to
what it was previously. I suppose I ust be missing something obvious :(
Is there a getter for the background color that I'm not seeing?

Thanks, Dave