Bandpass filter - indicator for MetaTrader 5

Theory :

Short description by John Ehlers :

The objective in cycle mode is to filter out the unwanted components – both low frequency trends and the high frequency noise – and retain only the range of frequencies over the desired swing period . A filter for doing  this  is called a bandpass filter and the range of frequencies passed  is the filter’s bandwidth .

Usage :

You can use the color changes as signals