I couldn't choose which color scheme, so you get both
Hellhound is a term that can be applied to a wide variety of sinister, ghostly or hellish supernatural dogs that appear in mythologies from around the world, particularly Europe and the British Isles. These supernatural canines all share a list of common attributes. Hellhound's are coal black and have eyes that glow bright red or on the rare occasion yellow. Some Hellhounds are no more then ghostly appraitions, while others are creatures of flesh and blood that attack travelers or lead them off the path at night to be devoured. In some stories the Hellhound will smell of sulfur and brimstone, travel great distances at amazing speed or even mimic human speech.
Hellhounds are always massive in size (ranging from the size of a horse to the size of a small rhinocerous). The dogs have been said to appear in large balls of fire or even glow with a blue light. Looking into their eyes or even hearing their howl can mean death. Some of the more responsible hounds are said to shepard the souls of the dead to the afterlife like a good dog herding sheep. In breed they can look like a Mastiff, Labrador, boar hound or even wolf like. Sighted in graveyards, near churches, and even on city streets the Hellhound is a phantom, a monster and a mystery.
Believe it or not to this very day there is a phenomenon known as black dog syndrome in which animal shelters have more trouble finding homes for darker colored dogs because of the stigma attached to them by years of superstition and negative portrayal in books and film. The idea of the black dog being evil is very ancient, and still lurks somewhere deep in our collective unconsciousness. Other submissions etc here