I've seen a few examples of things where there is white text on white backgrounds on Meta, and just thought I'd show a few screenshots.
Under a user page, the Favorites tab. Any newly-favorited (since the last time you viewed the Favorites tab) questions are like this. Same happens for the other tabs on the user page:
Links in spoiler tag blocks are a dark brown on the dark gray background of the spoiler block. As seen here.
The list of Responses on Meta display a light text on white background, but it seems they only display that way on new responses*:
The dates of events in timelines (
https://scifi.meta.stackexchange.com/posts/$ID/timeline) is in light gray over light gray.