This is how the Eeyore costumes have changed over the years.
Eeyore (pictured with Pooh) is more of a beige color, has short ears and has cyan outlining on his eyes.
Eeyore becomes gloomier and is more grey; plus his muzzle, belly and hooves become brighter. He sometimes has cyan outlining on his eyes and sometimes has a tongue.
1995-present: Eeyore becomes happier and his ears become longer and flatter. His stitches between the nostrils are thicker. He now has no tongue.
version of Eeyore, seen in live stage shows. This costume is performed on all fours.