Green can be easily beaten. He was made so he can only transfrom when your chracter is not looking at him. Simply have your character keep looking at Green and fire and you'll easily beat him without having to deal with his transformed states.
To kill Orange without him attacking you at all, simply slide into him constantly. He has a lag time before he can move again that is just long enough for you to get in another slide, thus letting you beat Orange effortlessly in order to save health for Green and Golden Silver. He IS, however almost immune to physical attacks, so it's take a minute or so to beat him.