STARC Bands Strategy

A type of technical indicator that is created by plotting two bands around
a short-term simple moving average (SMA) of an underlying asset's price.
The upper band is created by adding a value of the average true range
(ATR) - a popular indicator used by technical traders - to the moving average.
The lower band is created by subtracting a value of the ATR from the SMA.
STARC is an acronym for Stoller Average Range Channels. The indicator is
named after its creator, Manning Stoller.

WARNING:
- This script to change bars colors.