Here is Mrtools's Jurik Smoothed Momentum indicator for MT4 which can also be referred to as a Momentum Rainbow.

This indicator features:

• AHTF MTF (Auto Higher Timeframe Multi-timeframe) mode which also enables lower timeframes to be seen on higher timeframes.
• Custom Timeframe option
• Up to 6 different Momentum lines can be shown
• 34 Price Options including Heiken Ashi etc.
• Alerts
• Jurik Smoothing