The indicator was presented by Sylvain Vervoort in the October 2010 issue of Stocks & Commodities magazine. The article was awarded with the Reader's Choice award in 2011.

It begins by smoothing the price curve with a “rainbow” weighted moving average.

This smoothed price curve is used to calculate a RSI, which is then smoothed with the Vervoort zero-lag exponential moving average. The resulting curve is then transformed with an inverse Fisher filter.

Codes for various platforms have been released, the attached is my MQL4 port.

UPDATE 2011.06.24: Fixed refresh if Max Bars On Chart reached.