Personally, I’ve looked at it.
And while it seems to be good as A SOLUTION, I think Fermat came up with more of a geometrical based solution.
Sadly, he never wrote it down. Or if he did, it has been lost.
Fermat’s Last Theorem was finally proven a couple years ago, I believe.
My understanding is the “4-color map” question was answered in a brute force way, and not so much as proof.