Thanks! This does fix the issue when clicking on a palette color, but if you click on the primary or secondary color (at the far left of the status bar) a similar issue happens where the color is updated if that seems more complicated to fix then I'm fine to merge these changes though!

Thanks @cameronwhite . It seems to work correctly on my PC. Do you have a screen capture where I can see what you describe?

Sure, here is what I was doing:

Thank you @cameronwhite . I was not fully aware that one could change palette colors like that, but now I see how to do it and it behaves as expected on my end.

As for the primary and secondary colors, it's interesting that it behaves incorrectly on your machine, because it works on mine. I am testing Pinta on a virtual machine with Ubuntu Mate 24.04.1 LTS. What about you? It's worth asking, even though nothing here seems to me to be OS-specific (although I haven't looked in depth).

I was testing on macOS - I can do a bit of debugging on my end to see what's happening

I think the problem is that the OnNotify handler can be called sometime during Gtk.Window.Close(), so this can update the active palette color as if the user had clicked outside the palette window while leaving it open.

I'll test and commit a fix - we should be able to remove that event handler when closing like we do for some other events