I'm hoping they revert all the random unnecessary changes done to Raphael. They made for the perfect antagonist from personality to presentation. He has everything you could want in a villain. His brown hair suits his complexion and demeanor, giving him this... cinnamon spicy inviting appearance, which is half the allure and fun about him.
Demoting his horns down to a basic cambion also feels unfair to how heavy a presence he is.
He deserves to stay unique and away from overused tropes such as Black Hair = Evil man; it's too on the nose and looks and feels uncanny. It's amazing just how much a simple alteration in color and shade can completely change a character's entire perceived persona.
That and I would like to point out that Raphael's most recent concept art has him indeed with brown hair.