Hello!
Thanks for responding, but your response was not terribly helpful, as it denied the problem I am experiencing exists, even though there is something going wrong.
I indeed found the main stylesheet eventually (which was oddly not named “style.css”, but something else). The text colour was set to #ffffff, so I changed it. That still did not help.
Finally I figured out that the problem is with another plugin I am using in my widget section, TinyMCE. Apparently it’s a known problem that has no reliable fix at this point.
All best,
Rebecca