Its a me!

hurm what's wrong with hair coloring?

If you lookat my page you can see what possum pete's fur is like.

They have 3 layers actually,
Long silver guard hairs, medium black middle layer, and small white bottom layer. Also their skin is "pinkish" and resembles a doll.

Color is generally off when it comes to taxidermies. This possum has likely been dead for around 100 years. Even the small amount of sunlight entering the hall (it was very dim) and artificial lighting will bleach out the color after a long period of time.
Also, they have alot of rare/endangered/extinct animals on display. Those are likely to recieve the most time and effort when it comes to conservation. A possum, which is still fairly common, is likely to be a low priority.

ah i c. That would explain it then. My uncle's got a Red fox and Grey fox at his house that were Taxidermied back when he was young and went on a few "fox" hunts (not that I condone fox hunts but I did enjoy seeing the animal preserved in such excellent condition)