Calc has white text on light grey cell - can't change

I just started using Calc. Until I edited and saved a sheet, the text in Calc was black. Then all the cells that have a light grey background have text that’s white. It’s almost unreadable, but the white-background cells have black text.
I’ve tried changing both the background and the text colour to no effect. (I think the alternating row colours are embedded through VB, but the code is unreachable.)

What’s happening with the text colour?

We don’t know your document and can’t say. What makes you think that “the alternating row colours are embedded through VB”?

I added VB alternating rows about a year ago. I don’t see the code anywhere anymore, but the grey rows have continued. But the text should still be black.