This is usually a display/theme issue in Word rather than a document formatting problem, especially if the text looks wrong on screen but prints normally.
Try these checks in order:
- Check whether Word is using Dark Mode
- In Word on Windows, go to File > Account > Office Theme.
- Set it to Black only if Dark Mode is wanted, or use Use system setting.
- If the page background is dark and the text looks washed out, go to View > Switch Modes to toggle the page background.
- Keep the page light even if Office uses a dark theme
- Go to File > Options > General > Personalize your copy of Microsoft Office.
- Turn on Never change the document page color.
- This keeps the document page light while retaining the Office theme.
- Check Windows contrast settings
- If text and colors look unusual across Word, a Windows contrast theme may be enabled.
- Open Start, search for Contrast Themes, and set it to None.
- If the screen brightness itself feels harsh
- Open Settings > System > Display.
- Turn on Night light.
- Open Night light settings and adjust the Strength slider.
- If Word text looks inconsistent or oddly rendered
- Go to File > Options > General and turn off Optimize for compatibility, then restart Word.
- Then go to File > Options > Advanced > Display and enable Use subpixel positioning to smooth fonts on screen.
- If available, also disable graphics acceleration there.
If the issue started after a change but only affects how Word looks on screen, the most likely causes are Dark Mode, a contrast theme, or Word display rendering settings.
References:
- Dark Mode in Word
- Microsoft Word has the wrong page and text colouring by default - Microsoft Q&A
- Text and colour scheme has gone weird. - Microsoft Q&A
- Use color and contrast for accessibility in Microsoft 365
- MS Word Text appears to be different sizes although it isn't - Microsoft Q&A Why does the text on my Word document look as if the fonts are different sizes?