In RED the full minimum and maximum data received by the electronic components, a 270 degrees high resolution potentiometer for each axis. This is recognized as the minimum and maximum possible values for those axis.
In GREEN the calibrated values from each mechanical minimum and maximum movements per axis, which change from axis to axis. It is about 30 degrees on cyclic axis for example.
When every axis are calibrated, your inputs will be matching those value and full down collective on the Pro Flight Trainer will match full down within x-plane, but x-plane will still show the axis in RED, because it thinks that the axis could have a much higher range.