green ones is a pretty vague answer..are they zoas? button? or paly's?....most of my green anything do better in lower light though..
colour of zoo will pretty much dictate where it should go...i find anything blue, or with really florescent colour should be placed in lower light...my oranges purples and pinks like the sun though...
also you will want to make sure you have adequate flow past them...too much flow and they will grow long stringy skirts(but multiply like crazy)..too little flow and they will likely be choked out by algae...
i am pretty sure palythoa like more light then zoas too..