Yellow there will be change
Buy = crossover(up, down)
Sell = crossunder(up, down)
Below and above 0 trends can be viewed
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.
A history like that can really help people like me to understand the real application value of this indicator.
Hope it is possible.