I have 2 of these skaven in my war-band. They are heroes. Each one uses a different color on the claws.
Black: Primer, tribal marking, outfit
Metallic Sapphire: Bindings for the claws (on the unit shown)
Crimson Red: Eyes, blood on blades, Bindings for the claws (on the unit not shown)
Teddy Bear Brown: Fur and Tail
Tanned leather: Pants