You will need a larger texture for it not to look repeated unless your game engine supports semi transparent tiles and you can layer more than one. If you can do that and you can have slightly bigger or smaller tiles repeated then you can use the effect to eliminate all the repeating. If you cannot support it and have to have small tiles then all the features on the tile need to be very small in comparison to the tile size which may mean one or two pixels. So grainy green may be the best you can do.