How can I change smoke colour? I am trying to make a smoke simulation which includes colored smoke. I have tried changing the smoke color in the domain of the simulation, but the color in rendered view mode doesn't change from the default.
How can I change it?

Blend file: https://www.dropbox.com/s/1j4otu6dl6b7hnl/geyzer.blend?dl=0
Select the smoke flow object and in the physics tab, click the option that says "Smoke Colour" a colour wheel will appear. Using the colour wheel and the lighten darken option to its right, pick your desired colour. Things I did: 


added a white plane behind the simulation; it's easier to see. 
moved the camera to a better angle
changed the smoke colour in the smoke flow object, not the domain.