Excel font color changing to red automatically

Question

Excel font color changing to red automatically

Mihir 0

When I download an excel sheet it opens in Protected View and displays as expected. When I enable editing however, all the text turns to red. I also tested this with another sheet which I downloaded but this had another issue. All of the formatting appears to remain the same except for text which was originally a bright red, which automatically changed to dark blue when I enabled editing.

I have tried to clear all conditional formatting and there we no formatting rules on my sheet regardless. I disabled auto formatting in options which also didn't fix the issue. I found a similar post which mentioned moving the PERSONAL.XLSB file from the XLSTART folder in case its an issue with macros but I don't have an XLSTART folder or the file in my Excel folder within appdata.

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Answer 1

Kristen Tran 255 Independent Advisor

Hi Mihir,

I hope you're doing well today.

This type of behavior usually happens when a workbook's theme or style definitions become altered, either through the color palette assigned to the file's Normal style or through a corrupted theme component embedded in the workbook itself. Since this occurs consistently across different sheets and is not linked to conditional formatting, AutoFormat settings, or the PERSONAL.XLSB startup file, the cause is most likely tied to the underlying style or theme data stored within the workbook rather than to your Excel application settings.

Belows are some workarounds that suit for your situation:

1/ Reset the workbook's normal style

Open the affected workbook and enable editing.
Go to the Home tab, right-click the Normal style in the Cell Styles gallery, and select Modify.
Under Format > Font, set the color to Automatic, then click OK to apply this to the entire workbook.
Save the file and reopen it to confirm whether the text displays correctly.
Reference: Apply, create, or remove a cell style | Microsoft Support

2/ Review the workbook's theme colors and conditional formatting

Go to Page Layout > Colors and select Customize Colors to review the current theme palette.
Confirm the text and background colors are set to standard values rather than unusual or custom ones.
If needed, select Reset to return the palette to its original, default state, then save the file. Reset the Normal Cell Style
Reference: Change the appearance of your worksheet | Microsoft Support
Moreover, please check if there are any conditional formatting rules applied to the cells. Conditional formatting can override manual formatting. Go to the "Home" tab, click on "Conditional Formatting," and check the rules.

3/ Inspect and repair the workbook's theme file

Make a copy of the affected file and rename the extension from .xlsx to .zip.
Open the zip folder and navigate to xl > theme > theme1.xml.
Open this file in a text editor and check the <a:dk1>, <a:lt1>, and related color scheme tags for any unusual or incorrect hex values.
If any values appear altered, correct them to standard defaults (for example, 000000 for dark text and FFFFFF for light background), save the file, rename the extension back to .xlsx, and test again.

4/ Test in safe mode and repair Office if needed

Close Excel, then open the Run dialog (Windows key + R), type excel /safe, and press Enter. Open Office apps in safe mode on a Windows PC | Microsoft Support
Open the affected file in Safe Mode to see whether the text now displays correctly, which would indicate an add-in conflict.
If the issue persists even in Safe Mode, consider running an Online Repair through Control Panel > Programs and Features, selecting Microsoft 365 Apps (or Office), and choosing Change > Online Repair.

I hope this information is helpful. Please follow these steps and let me know if it works for you. If you have any updates regarding the issue, please feel free to share them with me.

Thank you for your patience and your understanding. I look forward to continuing the conversation.

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Mihir 0 Reputation points

2026-08-04T15:56:01.01+00:00

Hi Kristen,

Thank you for your suggestions! Workarounds 1 and 2, resetting style color and conditional formatting, did not work for me.

When trying to follow your steps to repair the workbook's theme file, I was not able to open the folder once I renamed it to zip. I then downloaded a different zip app and the only file inside of the zip was a Workbook file.

Opening Excel in safemode was the only workaround which worked after testing it on both of the workbooks which were changing formatting. I'm not sure what safe mode does exactly or if it's realistic for me to always open all my workbooks in safe mode though.
Kristen Tran 255 Reputation points Independent Advisor

2026-08-05T05:29:42.5466667+00:00

Hi Mihir,

Thank you for testing those steps and sharing the results.

Since both affected workbooks behave normally when Excel is opened in Safe Mode, that suggests the issue may not be caused by the workbook’s formatting or theme itself. Safe Mode starts Excel with several normal startup components disabled, such as add-ins, startup files, and customizations, so it is mainly useful for troubleshooting rather than daily use.

The next step would be to identify what Excel loads in normal mode that is not loaded in Safe Mode.

Please try the following:

1/ Disable COM add-ins

Open Excel in Safe Mode, then go to File > Options > Add-ins. At the bottom, next to Manage, choose COM Add-ins and select Go. Uncheck all listed add-ins, close Excel, and reopen it normally.

If the issue is gone, re-enable the add-ins one at a time until the red font behavior returns.

2/ Check Excel Add-ins as well

Go back to File > Options > Add-ins. Change Manage to Excel Add-ins and select Go. Uncheck all add-ins, then restart Excel normally and test again.

3/ Check the Excel startup folder

Press Windows + R, then open this path:

%appdata%\Microsoft\Excel\XLSTART

If there are any files in that folder, temporarily move them to another location and restart Excel normally. If you see PERSONAL.XLSB, you can temporarily rename it and test again.

Regarding the workbook theme repair step: if renaming the file to .zip only showed one “Workbook” file, it may mean the extension was not changed correctly, file extensions are hidden, or the workbook is not in the expected .xlsx or .xlsm ZIP-based structure. Please make sure you are working on a copy of the file, enable File name extensions in File Explorer, and confirm the file is an .xlsx or .xlsm file before renaming it.

However, based on the Safe Mode result, I would focus first on add-ins and Excel startup items.

Hopefully these steps help narrow down what is causing Excel to change the font color automatically. Since Safe Mode works, I'm likely getting closer to the source of the issue. Please update me with what you find after testing the add-ins and startup folder, and I can continue troubleshooting from there.

Warm regards.
Kristen Tran 255 Reputation points Independent Advisor

2026-08-06T07:38:54.7066667+00:00

Hi Mihir,

I hope you're having a good week.

I'm just checking in to see if there have been any updates on the issue. I hope things are moving in the right direction and that a resolution is near.

Whenever you have an update, I'd be grateful if you could let me know.

Thanks again for your help and time.
Mihir 0 Reputation points

2026-08-06T21:03:03.8066667+00:00

Hi Kristen,

Yes the issue has been resolved! I had followed your suggestion to launched Excel in safe mode and this fixed it. After this, even when I opened Excel normally I haven't faced this problem again.

Thank you!
Kristen Tran 255 Reputation points Independent Advisor

2026-08-07T04:41:31.4033333+00:00

Hi Mihir,

Thank you for your update.

I'm glad that starting Excel in Safe Mode helped resolve the issue and that Excel has continued to work normally afterward.

If you have a moment, please consider marking the reply as the Accepted Answer by clicking Yes. Doing so helps other community members quickly identify a solution when they encounter a similar issue.

Thank you for your cooperation. If you have any other questions or need further assistance in the future, please don't hesitate to reach out. Warm regards.