Minecraft wiki entry for Sheep, associated text: The foot of a sheep.
The sheep's color around their face and overlay when sheared corresponds to their wool color.
A sheep before Pocket Edition Alpha 0.6.0.
Pink sheep before Pocket Edition Alpha 0.8.0.
All of the possible sheep wool colors (dyed by the player.) Sheep have dyed wool remnants.
A yellow sheep during Pocket Edition Alpha 0.7.1.