In Microsoft Word, you usually can’t directly choose any custom text selection color from Word itself. On Windows, the selection highlight is controlled by a Word/Windows setting, and the most common workaround is changing the NoTranslucentSelection registry value for Word.
Change the selection color Press Win + R, type regedit, and press Enter.
Go to:
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Word\Options
Create or edit a DWORD value named NoTranslucentSelection
Set it to:
1 for a solid black selection highlight.
0 for the default gray/translucent selection highlight.
Close Registry Editor and restart Word, or restart Windows Explorer if needed.
