When I use quick effects -> quick smoke to create my domain and stuff for me, I have had trouble if I made a mistake as to wether I wanted smoke or fire, and then tried to change it later. Once it is created, there seems to be no way to visually change it from smoke to fire. Even if I get all the physics working right for fire, all that renders is the small amount of smoke emitted by the flames. Setting up the solid viewport color for flames demonstrates the physics side is working because the flames do fade upward like they should.
How can I make a quick effect smoke domain have fire in it after it has already been initiated for smoke?