On my personal Mac, all top level rendered Markdown body text appears as red text.
On my work Mac, it appears correctly. Even looking at the same Markdown files on both.
I’ve tried explicitly setting a body text color in my CSS, and it doesn’t make any difference. I’ve also tried not having custom CSS, and that doesn’t help either.
I worked it out. The style sheet for the web (Web tab) was being applied to rendered Markdown, not the style sheet for Markdown.
(I don’t remember exactly why I had set up red top level text for my web style sheet… Something to do with debugging a page saved as an all-in-one HTML file I think?)