Hi Hakon, welcome to the Community! I think there are a few articles that can help you with adjusting the report colors: this article is about the color settings in reports, and this article is about setting the colors in Scorecards specifically. 

Thank you for this Lila - I’ve read those articles before, but I still can’t see how I can color a field in a tabular report like the screenshot I pasted (this was from your COVID presentation). Do you have a link that explains how to do that?

Did you try to make this a mass edit report vs. a standard report? By selecting the Scorecard Fact object, you should see this dropdown.

Thanks - now solved it!:)