You have to apply this script to usual candles and not Heikin-Ashi!!!
Background color indicates HA bar color. On change you'll see green/red arrows and alert will be fired.
Also you can find in the code calculations of all HA OHLC values.
Pine Progr: https://qntly.com/pineprog
Adv.Pine Use-Cases: https://qntly.com/advpine
Access to Pro Indic.: https://qntly.com/proind
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.