[JL] EMA Trading Zone

I want to make a script to help catch pullback on a strong trend.
This script display colors based on EMAs' slope.
The trading zone is calculated from EMA short + - ATR
if 2 EMA lines' slope both are more than an angle, then the trading zone is green color, it can be considered to place long orders.
if 2 EMA lines' slope both are less than a negative angle, then the trading zone is red color, it can be considered to place short orders.
Otherwise the zone is blue color.