Where can I buy shoe dye?

I can only find my bridal shoes in a dyeable white color (satin & crepe luxe material) online, and I can't find them at a bridal store like David's so they won't dye them for me. I need to dye them myself but I can't figure out what kind of dye to use or where to even get it after all the googling I've done. I want them to be ivory to match my dress. Where do I get shoe dye? What kind?