When you say 'everything' do you mean the background as well?
Sprites are easy enough (technically), but the background is a whole different thing. If you had a tree as a solid, would you want the ground behind the tree to be grey? If so, I would expect that would be beyond capabilities.
It might help if you show on your screen shot what you would like to see in detail.
YES I WANT SPRITES AND BACKGROUND BE GRAY,LIKE THAT IMAGE I POSTED
IS THERE A WAY TO DO THIS WITH EFFECT?