List of steps to reproduce (step by step, including full links if applicable):
With the Wikipedia iOS app, go to https://en.wikipedia.org/wiki/Grey%27s_Anatomy_(season_1)#Episodes.

What happens?:
Note that the table header is completely black, aside from the gray lines dividing cells. The header text is there, but it is also black like the background color, so not visible. Screenshot below.

What should have happened instead?:
Not totally sure how it works but I'm guessing the template has code that automatically decides if the text is black or white depending on the background color (specified by the user). This seems to not be working here, and always producing black text regardless of background color.

Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc:
iPhone 13 running Wikipedia iOS app 6.8.1 (1815)