The only thing about fire is that it gets bright, so the more overexposed it gets, the less color you will see in the flames (as opposed to the color of the light it shines on the subjects, which is less bright than the flames themselves.) Think of the flames as the light bulb inside a lamp.
Therefore the more you stop down and underexpose the fire, the more color you will see in the flames, but also, the less exposure you will get on anything the fire is lighting, just as when you stop down to see the filament inside a light bulb.
There's no right or wrong stop to shoot at. The general approach is to simply light the scene to the highest light level you can practically achieve in order to stop down the lens and hold more color in the fire. For the exploding building in "Terminator 2" for example, they lit the night exterior up to f/5.6 on 500 ASA film so that the explosion would not get too overexposed. Or think of the burning wall collapsing in the Atlanta scene in "Gone with the Wind" -- it is very red because the 3-strip Technicolor process was very slow back then (and daylight-balanced). Imagine shooting a fire on 10 ASA film at f/2.8. for example, to get an idea of how much exposure a fire would get back then. "Backdraft" shot most of its fire scenes on 250 ASA daylight film and used daylight carbon arcs to get the shooting stop higher so that the flames would expose more like a deep orange rather than an overexposed white.
If you are shooting video, a camera with better dynamic range shooting in Log or RAW mode will hold super-bright details better than a standard Rec.709 broadcast camera would.
