Excel window opens colored grey instead of green

Question

Hi, I have the latest build of Office Home & Student 2021 (Version 16.102.2) on the latest MacOS release (Tahoe, 26.0.1). I am having an issue with Excel where whenever I open an existing spreadsheet, the file window opens with a grey color in the bar above the ribbon, like this:

If I were to, then, minimize the window and re-expand it or mouse over to a different window or open the preferences, it would then change over to the correct green color:

Neither of the other Office modules (Word and PowerPoint) are behaving like this. Both are opening windows in the correct color associated with the app (blue and red, respectively). Only Excel is doing this. No functional issues with the app. It's just, visually, annoying. Any ideas what's going on or how to fix it? Thanks.

Answer 1

I haven't jumped on the Tahoe wagon so I cannot confirm but this sounds like a UI compatibility issue which needs to be addressed at the developer level. I know of nothing in the program which would account for such behavior. It's almost like it's erratically switching to something similar to [but not exactly] the Aluminum Office Theme

While the issue is displayed use Help> Feedback in the Excel menu bar to report the issue to the Microsoft development group. Check the box to include a screenshot. Apple should be notified as well.

Answer 2

I'm running the last version of Excel 365 and Tahoe 26.1 and have this bug. Already submitted feedback using the "Help" menu.