Rough proof that Gold Tipped Black is
recessive to Dusky Blue Tipped White:
We know that Lilibet (starter) hides GTB, from previous kittens from her. Put her with a kitty with DBTW, and the kitten comes out with DBTW.
Since we know daddy passed his DBTW to the baby (it's showing), that means the kitten has to be hiding GTB since Lilibet can only pass Silver or GTB.