These button colors should be used exclusively with System Call to Action promtpts directed to, and from the user. Below are examples of current in-situ CTA in use on Single Page Applications, where this caterogy is especially useful.
There are two sub-categories of CTA buttons. System Commands, and System Requests.
System Commands are CTA that do work for the user (Create X, Go to X, Find X - Clear)
System Requests are buttons that prompt a response from the user (Did this help? Did you find what you were looking for?)
Azul will be used to represent System Commands, and Coral will be used to represent System Requests.