This oscillator is a variation of the well-known Awesome Oscillator.
I have added an extra oscillator line that plots the difference between the EMA's of the short and long periods.
This adds an extra warning of a trend change since the EMA line will usually lead the SMA histogram and sometimes contradict it.
The times when a contradiction is indicated are times to be extra cautious.
I also prefer using periods 3 and 21 for the moving averages, rather than the standard 5 and 34.