No hadn't heard of it, I don't follow copyright law extremely closely it tends to make me annoyed. On it's face reading the case summaries and looking at the two pictures, it feels like the act of manually repainting and the color choices should be enough to render it a transformative work. It's one of the fundamental problems with trying to apply copyright to anything other than precise copies, art remixes and recombines all the time, it's fundamental to the process.
It is current at the SCOTUS so we should see a ruling for the USA sometime in the next year or so.
https://en.m.wikipedia.org/wiki/Andy_Warhol_Foundation_for_t...