From the screenshot it looks as though you are using the server version 2.9. The green image is a known issue with that server version. It is particularly likely to happen when there is low light at the sample, and as you say it gets stuck green and does not resolve easily. You may not need to completely re-install, using
sudo ofm reset
sudo ofm restart
will clear most of the calibration from the server and can give the calibration a fresh start.
The issue is resolved by a new calibration routine in the next version of the microscope server software. That is currently a beta release. Release notes and how to install are on the threads Software Beta release (the Beta1 that has been out for a while) and Software release v2.10.0b2 a beta2 release with some extra functions.
sudo ofm update
sudo ofm upgrade --pre
will give the current latest pre-release (beta2). If you want beta1 which has been used more there is a way to do that using the actual version number, but I am not sure of the syntax.
Edit: layout of server commands