This is the standard Heiken Ashi, but with the option to spot Dojis and color them differently.

Basically, if the body of the candle is less than a certain percentage of the total range for that candle, then it's a doji. That's the premise behind this. A Doji for Heiken Ashi is typically almost no body at all, with a long head and tail. I default the value to 10% of the total range, but I personally have been testing with the value at 4%. YMMV.