Smoke simulator temperature decay I know that I can control the colour of smoke with its temperature, but the temperature of the smoke keeps decreasing over time. I want it to remain constant, so that the only changes in smoke temp is when smoke from two different temperature emitters mix together. Is there away to control that?
I assume that you use cycles render in blender.
If you used the quick smoke effect by adding Object/quick effects/ quick smoke you can try to set the color of the flame by: 


selecting the Smoke Domain of the fire emitting object 
open the node editor 
change the color of the flame in the ColorRamp settings.


Using more than one Smoke Domain means that you can have several color settings and combine then in your scene.