I think to have done a good work...
Here you are a perfectioned Joker action figure, as he was when portrayed by Heath Ledger.
I started from a Mattel "punch pack" Joker figure and I sculpted scars; then I repainted the face to get a make up effect (I used gloss paint); then I repainted a part of the hair (to get the same effect); I repainted the neck (in the base figure it was white too); finally, I added a bit of white on the jacket and I repainted the tie.