Your on your way to to create your own rainbow sheep in minecraft ! First in creative mode gather the following materials anvil,nametag an a sheep egg.
Step 1: Create the Nametag
Place the nametag into the anvil an in the typeing box enter "jeb_".
Step 2: Rainbow Sheep!
Place your sheep egg an use your new nametag on that sheep. Tada! the sheep will now turn a wide array of colors.