Screen problems

[kenny83]

I just got a viewsonic 22" fullhd monitor the desktop resolution is 1920x 1080. there are 2 modes pc mode and hd mod when i put it in hd mode the screen goes bright greenny color u can still see the pic behind it i dont have a blueray drive but i have hd demos on my pc wich play through VLC player any ideas why it does this