You can change the text, don't think you can change the positioning. You could make the positive text read "cancel" and the cancel text read "OK", as long as your code handled the correct result value.
I haven't explored what happens when you provide "" for all three buttons - you'd probably need to provide a custom layout that included buttons and handle the button events yourself.
You could probably change button color using the .GetButton method of CustomLayoutDialog - I've not yet tried it. You might also be able to change position ...
You could probably change button color using the .GetButton method of CustomLayoutDialog - I've not yet tried it. You might also be able to change position ...