Outlook misspelled word Highlights black

Hi @Runquist, Travis M,

Thank you for posting in Microsoft Q&A Forum.

Regarding to your description, I've also tested the behavior on my end (you can see these steps below) and experienced the same issue, therefore, could you kindly confirm if what I observed matches your experience?

1- When using the Light Theme, I created a new email and typed a misspelled word. It was highlighted in red, as expected.

2- Then, I switched Outlook to Dark Theme. The highlight changed to a white-red contrast, which looked fine. However, when I enabled the white background toggle, the highlight reverted to the light theme style.

3- While staying in the message editing pane, I turned on white mode in Outlook settings and saw the same issue you described, misspelled words became difficult to see.

If that the case, as far as I know, the issue may come from syncing setting in Outlook. And I notice that you're tagged the question with New Outlook, therefore, I'd suggest you try the work around to reset theme setting by follow the instruction below. If my understanding is incorrect, please feel free to correct me again so we can work together to find the suitable solution.

To reset the theme syncing, please follow these steps below:

With the New Outlook desktop app

1- Config your device system theme to white mode (if not already).

2- Open Outlook, go to Settings > Gerneral > Appearance > Use system settings > Save > Close app

3- Open the app again and create the new email then check the issue still persists. If it work normally, you can change the theme back to Dark mode and save the setting.

With the Outlook on the web, please check if your browser is using Dark Theme. You can try the same steps above to reset the theme settings.

This issue also seems related to Windows behavior, so I want to thank you for sharing your experience and I strongly recommend submitting feedback via Outlook (image below) or through the Microsoft Feedback Portalthen feel free to share your feedback link in this thread so other who have the same situation are researching in this community can address the information more quickly.

Thank you for your time and cooperation. If you have any further questions or concerns, please don’t hesitate to let me know.

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