The Harmony automatic shifting system works by sensing your cadence (rate of pedaling) as well as wheel speed, and making small constant adjustments as you ride to ensure the most efficient gearing possible. The BLUE mode on the shifter indicates Automatic operation, while the ORANGE mode is Manual mode, which shifts just like a regular bicycle. You can switch between BLUE and ORANGE using the silver button.
When you’re in Orange mode, rotating the shifter AWAY from you makes it EASIER to pedal - rotating it TOWARDS you makes it HARDER to pedal.
When in the Blue mode, we recommend leaving the shifter in the ½ way position, which will provide a smooth and easy ride.
Take a look at the blog post linked below that highlights this in a bit more detail: https://www.evelo.com/blog/continuously-variable-transmission-cvt-on-evelo-electric-bikes/