Theory :
EMA (Exponential Moving Average) is very well known and widely used indicator. More information on it can be found here :
This version :
Is using the “Fast EMA” variation (originally published here : Fast EMA) instead of using “regular” EMA for TRIX calculation. That makes it faster in response to market changes than the original TRIX indicator
Usage :
You can use this version the usual way – change of color can be used as a signal