your plants look ok.. a bit over watered.. but not too bad.. the new lighter colored growth is pretty normal.. it should darken as it come out more... i dont recommend flushing until the end of the grow before harvest.. and that should only be the last week or so, if that.. i dont think h202 will help with moisture problems.. the added oxygen is good for the roots.. but it will kill the soil beneficials.. so its not always a good thing.. if you do use it add it to your water/nute solution... if there is anything else you have questions on just ask!