help configuring Excel in dark mode to view black cells properly (Office Professional Plus 2021)

Office Professional Plus 2021 does not support Word-style dark mode for Excel (view-only dark mode that preserves cell fills and formatting for others - cannot fully emulate Word-style dark mode), so far I know.

Microsoft introduced this feature in Office 365 / Microsoft 365 subscriptions with the “Dark Mode with true cell fill preservation” feature, but it’s not available in the standalone installable versions like Office 2019 or 2021.

If you must stick to Office 2021 Pro Plus:

• Use lighter fill colors for black cells temporarily while working in dark mode.
• Adjust gridline color to improve visibility.
• Avoid fully black fills if you need to see them in dark mode.

If you want true Word-like dark mode:

• You’d need Microsoft 365 subscription.
• Any installable Office standalone version (2019/2021) cannot provide this feature.

Workarounds in Excel 2021 (to make black cells visible for yourself only):

• Change gridline color: Makes dark cells stand out more.
• Temporarily adjust fill colors (e.g., dark gray instead of black) for your session.
• Use Windows High Contrast theme (system-level workaround).

Hope this helps at least a little bit.