Problem with Monitor, flickering green
It is not clear it is the hardware (your screen) but the Safe mode indicates that.

things you can try


Disable Automatic Graphics Switching
run Apple Hardware test.. Press D during startup
disable any graphics controllers (external software) like the TechToolPro
Reset PRAM/NVRAM..press Option-Command-P-R until you hear startup sound a second time.
reinstall OS
NONE of the above worked..lets get to the final step..Hardware.. it might be the Cable..see instructions here how to get to it, just pull it out and back in, while you are at it vacuum clean the interior. 


This is considered a Very difficult surgery, so if you are not of a steady hand and very handy with tools, skip the step and go to professional place.