I love the color in Hammer's The Gorgon, as well as Brides of Dracula and Kiss of the Vampire. I USED to love the color in Horror of Dracula, too--before it went Blue in more than one way.

Certainly Forbidden Planet, while not being a horror film, looks beautiful in gorgeous color. House of Wax, too...and Phantom of the Rue Morgue, when I can find a good print.