Reproducible: always
Is a regression: no
Platform: Windows 7, Windows 8.1, Windows 10 (successfully reproduced on all of them)
Steps to reproduce:
1. Add TextEdit to a scene and set placeholder text with setPromptText
2. Enable high contrast mode by pressing Alt-Shift-PrintScreen
Expected result: Placeholder text is still visible.
Actual result: Placeholder text is invisible (black on black)