Ive seen people do it before, but have no clue how.
What do you have to do?
Also, what type of die do you need to make it permanent?
I dyed (died?) the tummy of a Tie-Dye Furby purple. It turned out a sort of lightish pinkish color. There's some special kind of dye you have to use.
Beware of furbys in unknown gens, they are fake... (an all blue might just be a dyed white)