Dark Stains-Two Bears of Deck/Boat shoes-any way to salvage?

Two different pairs of deck shoes-one Rockport..One Sperry Topsider.
Both are relatively light brown. The Rockports are about two years old-I was understanding of a stain with them. The Sperry's were brand new.
I have NO idea what could have caused the stain/discoloration on those shoes-I only wore them on Mother's day and wore them visting-I wasn't tramping through sludge or being harsh on them.

The areas around the toes are a dark color-no matter how much polish I put on them, it doesn't remove the dark area. Tried some dye-that doesn't work either. The new Sperry's were around $80-I am not sure what to do. I hate to keep throwing money down the drain for shoes.

Is there anything I can do-something I can try I haven't tried to try to restore them? I wish I knew what caused the stain-it was nothing apparent.

Let's have a look at some pictures, please!

And we can go from there.

Roger Koh
Leather Doctor®