Smoke simulator not changing to the textures I select

I added a new material and switched it to volume and then I selected texture and changed it to voxal data. I want to give the smoke an orange glow and when I select ramp and then select my domain cube it says my coloring is good, The dark box to the right shows and orange and gray but when I go to render I get just gray smoke, any suggestions on what I am doing wrong?
Thanks