Vervoort Heiken Ashi Candlestick Oscillator

Heiken-Ashi Candlestick Oscillator (HACO), by Sylvian Vervoort, is a digital oscillator version of the colored candlesticks.

Explanation from Vervoort:

"HACO is not meant to be an automatic trading system, so when there is a buy or sell signal from HACO, make sure it is confirmed by other TA techniques. HACO will certainly aid in signaling buy/sell opportunities and help you hold on to a trade, making it more profitable. The behavior of HACO is closely related to the level and speed of price change. It can be used on charts of any time frame ranging from intraday to monthly."

HACO has 2 configurable length parameters - "UP TEMA length" and "Down TEMA length". Vervoort suggests having them the same value.

I have also added an option to color the bars (overlay mode).

More info:
[S&C 2008/12] Trading with the Heiken-Ashi Candlestick Oscillator - Sylvian Vervoort

List of my other indicators:
- GDoc: docs.google.com/document/d/15AGCufJZ8CIUvwFJ9W-IKns88gkWOKBCvByMEvm5MLo/edit?usp=sharing
- Chart: tradingview.com/v/4IneGo8h/