I am trying to make an image with black fire against a white background but whenever I change the color ramp to black the fire just disappears, any help is appreciated.! This is the node set up I have for the color (https://i.stack.imgur.com/qWJcw.jpg)
I suggest watching the fire tutorial. It gives a lot of good information on how to create good looking fire. The video is titled How to "Render Fire in Cycles".