I think it is better to check this in one task instead of different tasks for encrypt and decrypt / verify
Edit 2025-07-22:
This ticket is now dedicated to the improvement of the contrast of the result windows in kf5, as T6869 (which has further improvements) can not be backported.
For this task:
- remove the blue background color so that the text is always black on white for "neutral" results (Test: check encryption and decryption results)
- for the negative results keep the light red background, but with a black font (instead of dark red). (Test: Check in the notepad with sign only)