I will be painting the World Eater in a deep red, with a bone white helmet, to represent a Chaos Space Marine of the Skulltakers. I still don't know what colours I will use for the Hive Tyrant. But I think green would be nice, to give it a strong contrast to the red.
My 2nd entry will be a Great Unclean One for the monster category.
My latest Ebay order arrived earlier today. It is some Forge World bits for my World Eater command squad, and Biohazard Helmets from Maxmini that will be used for a squad of Plague Marines.