Safari Menu Bar goes black for _some_ sites (Big Sur)

I had this problem as well as soon as I upgraded safari. It took days of conversation with Apple support (the rep was equally confused). Finally, we stumbled on a solution, although I have to say why Apple's Safari upgrade caused this to happen is mind-boggling.

To fix this, go to Safari>Preferences>Tabs and "un-click" Show Color in Tab Bar. That should do it. Note to Apple: Please don't engage things in your updates without first advising users how they can opt out.

Hi PQuincy,

Thanks for coming to Apple Support Communities for help today with Safari. It sounds like you are concerned that on some sites the menu bar is black.

This may be normal. Have a look here: Change Tabs preferences in Safari on Mac. What do you see in Safari > Preferences?

"Show color in tab bar

Use the color of the website as the background for tabs."

Is this preference on?

Do you have Light Mode enabled on your Mac: Use a light or dark appearance on your Mac?

Have a fantastic day!

thank you for asking this and posting the answer! I am finding that the 'tech help' is uninformed and there is no adequate answer unless you spend, as you did, DAYS of investigation to get it. That apple has made these changes without out consent and THEN makes it impossible to find an answer or remedy it just shows how LITTLE they care about the customer now. We don't all want the changes to how our computers function and appear. Just because they think some new trend is cool, doesn't make this "up" grade anything but a downgrade in my opinion. I don't have the time to go on a scavenger hunt for answers. I applaud your perseverance for doing it!