What is it called when an animal uses bright colors to warn predaters of danger

Like with the coral snake and the poison dart frogs.

Warning colouration is the exact opposite of camouflage, its function being to render the animal conspicuous to its enemies, so that it can be easily seen, well remembered, and avoided in future.

Warning colours are associated with some quality or weapon which renders the possessor unpleasant or dangerous, such as unpalatability, an evil odour, a sting, the poison-fang, etc. The object being to warn an enemy off, these colours are also called aposematic.