[red-tea]

No. This is a different thing. The problem is when people haven't coded their CSS correctly and assume default background is white and then set a non default foreground of black or something. Those sites will still break for dark themes even with this API.

In fact, if people actually understood the first C in CSS, this thing wouldn't even be necessary.

[leppr]

Dunno why you're being downvoted. This indeed is a very widespread problem. Even some Google services (like Google Docs) have it.

[mixmastamyk]

It generally happens when the site specifies the forgeround or background color but not both, leading to very low contrast.