Is there an option to stop AI using liveries from livery designer. I recently started a new one and then saw it in timetable mode on SEHS. I have done liveries on the ICE3 but have never seen it on AI in timetable mode.
No there isn't In some routes liveries will spawn on AI trains (SEHS, LGV, SPG, ECW) but on SKA and HMA no train has your livery.