The skin of the scythe depends upon its rarity. Gold scythes will have 4 claws, purple scythes have 2 claws, and white and blue scythes have a single claw (there are exceptions to this rule as purple scythes rarely come with 4 claws or 1 single claw).
The PvP reward version of the single claw version is known as a Lesser Ancient Scythe.
Dye will affect the handle of these scythes and the tips of the claws (except for the "common," single-clawed skin which lacks the dyable section on its blade). Their default color is yellow.