advice on dying leather?

HELLO FOLK.

I have an item that is leather and is currently "forest green". I would like to do it an after-market treatment to make it more teal. I think, from poking around the internet, that what I want is something like Angelus leather dye or Fiebing's leather dye. Does this... work? Is there other stuff I need to get? I keep trying to look it up and getting overwhelmed and closing the browser window, you see...