The ride capsules are mounted on a centrifuge to simulate G forces. When the ride opened, there was only one version, but so many people became ill that they changed it to offer 2 versions.
The Orange version includes motions plus the spinning centrifuge, which spins at various speeds and at various times to simulate the G forces.
The Green version includes the same motions, but not the spinning. In order to reset the ride, the centrifuge needs to make one complete revolution during the course of the ride. The one revolution is not noticeable to most people at all, but that combined with the other motions, the closeness and the sounds may be why some people feel it's very theme and others get dick from even the Orange version.
The recommendations to avoid getting sick for both versions is the same - look straight ahead, don't turn your head and keep your eyes open. Motion sickness occurs because the motion your body feels doesn't match what you see. When the brain tries to interpret those conflicting 'messages' , the result can be illness.