Brushless Motor Encoder Read?
I found a data sheet for a different MegaMo motor.  It seems to have similar wiring, with the following specs related to the encoder connector:

A Hall Sensor         Blue 
B Hall Sensor         Green 
C Hall Sensor         Yellow
+6V Logical Supply    Red 
GND Logical           Black


(from the BL2235 datasheet)

This should at least get you started on reading the encoder.  Couldn't find anything more detailed about the sensors/resolution.  Hopefully you find this helpful.