If you have had experience with gas lanterns you know that the flame burns blue until the mantle is lowered over it and then it burns bright yellow. I do not think that sodium is involved for camping lanterns.
You are right - no sodium.http://en.wikipedia.org/wiki/Gas_mantle
Red hot, white hot refer to light emitted by hot substances, their color can be approximated by black body radiation, seehttp://en.wikipedia.org/wiki/Black_body
However, most real life substances differ from the black body (in terms of quality of the approximation), so their emmision spectra (and I mean thermal emission here) differ from the one described by Planck's law. It happens that substances used in the gas mantle differ in such a way that they emit more in the visible range at the price of lower emission in other ranges. That's OK, as in lamp we want as much of the energy as possible to be used for light, not for heating.
In the case of Bunsen burner flame color depends on the amount of air (oxygen) mixed with the gas, but most of th elight comes from the black-body radiation. If there is not enough oxygen, combustion is not complete, there is much more hot soot that can emit light. Soot is reasonably close to the real black body. Sure, if there is not enough oxygen the temperature is also lower so the flame is more yellow and red then white. Highest temperature that is possible in the Bunsen burner is in the range of 1500 C - that's still far from the really blue, which needs temperature in the range of several thousands. So the blue color visible is not from the black body radiation, I recall reading something about hydrogen emissions - but that's completely different story.
However - gas stove has burners that are made to use always the same mix of air/gas in the right proportions. You can't change these proportions easily - the easiest way I can think off is to boil over milk and not clean the stove later
So as long as the burner is properly working, flame has rather constant temperature and it can change color only due to some other reasons. Sodium being one of these.
Then, don't treat me as an authority. I am known to be occasionally wrong