Not chocolate I know but who remembers those red, green and yellow round cookies in the mid-late 70's called spooks or spookys (something like that) I do and scoffed loads of em!
No, these were spooks.
Julie Hardcastle wrote "These biscuits were round, sweet, plain biscuits, and the novelty was that each one was a different colour! Each colour had a monster-themed name, such as Red Devil, Green Gremlin, Orange Ogre etc. I seem to remember yellow and purple ones too." Russ Litton who remembered their name said "They came in various garish colours and each biscuit had it's own individual name - Ghastly Green, Blood Red etc etc"