Heiken-Ashi Color Vts

// Simple as it says:
// gives you the color of the Heiken Ashi candles in a separate panel.
// I needed this indicator since in TV switching from HA to normal candles resets the chart and I had to go back manually.
// This solves the nasty issue.
// Moreover, nobody enters/exits the trade on the HA values but everyone uses just their color, right?
// Since bearish candles are encoded with value -1 and bullish candles with +1,
// a simple average can be defined (if you don't find it useful, disable it).
// Vitelot-Yanez-Vts, Aug 2020
//