I like the After on your initial post the best, so your proposed change should be applied.

In DatabaseWidget::performSave() we should be disabling the preview widget as well. It might just be more effective to disable the entire DatabaseWidget itself (ie, just call setEnabled(false)) instead of disable individual sub-widgets.

We don't disable the main window because you can switch tabs during save operations without impact to saving. Technically we can do the same when issuing the yubikey notice message, but we didn't.

Saving happens literally in milliseconds even on weak arm devices, I don't think you can somehow manage to do something in that time. If the database is protected by yubikey, a popup notification appears first, disabling all elements, and only then the save takes place. Right now it is impossible to achieve uniformity of colors in different operations. With my edits I fixed the colors only when saving, removing from the styles the elements that did not match the color when they are disabled, but when the pop-up notification from yubikey appears, the colors do not match again, since all elements are disabled here. The easiest thing to do without editing the base style is to just disable everything during save operations. Or disable the same elements when the yubikey popup window appears, but here you will have to change the base style as well.

I'm not sure why we disable the main window when waiting for yubikey press

I tested with disabling the screen when saving to show how it would look. It turned out just perfect, without any additional edits to the base style.

DatabaseWidget::performSave()

QWidget *mainWindow = this->window();
if (mainWindow) {
    mainWindow->setDisabled(true);
}
QApplication::processEvents();

if (mainWindow) {
    mainWindow->setDisabled(false); 
}

I said to not disable the whole main window, just the database widget itself.

I see what you're suggesting, that you disable DatabaseWidget, but that won't change anything, the colors won't match either. I suggested what I think would be better to do with minimal code changes is to disable the window. I don't understand why you are against it? The database and its changes are saved instantly. You won't have time to switch to any tab. I don't understand what practical sense it makes to leave any element enabled when saving?

We disable the window during the key transformation and save operation, because there is no safe way we could modify the database at that time. I believe external reload triggers are also disabled for the duration. We had a few bugs in the past when users messed with their database while it was being saved. Hence we prevent modifications during saves and disable the UI to reflect that. The YubiKey button press occurs somewhere in the middle of that.

Thank you, I will check it out when I get a moment