Attaching three screenshots so you can see this visually.
This is an email that came in via Outlook. It looks correct in Outlook (first screenshot).
I brought it into DEVONthink. In dark mode, the background is white with white text, so it’s pretty much unreadable (second screenshot).
If I switch things into light mode, it appears properly (third screenshot).
Is this a bug? Or is there a setting I can tweak somewhere to make it display properly?