User Configuration > Administrative Templates > Microsoft Project 2016 > Project Options > Schedule > Scheduling options for 'Project1'
User
HKCU\software\policies\microsoft\office\16.0\ms project\options\scheduling
This policy setting will allow the display of green task suggestions to indicate potential optimization. If you enable this policy setting, a green task suggestion will be displayed to indicate potential problems. If you disable or do not configure this policy setting, a green task suggestion will not be displayed to indicate potential problems.