hey there MC, new calyxes are totally normal, there is no indication by them of ripeness . white calixes sometimes turn after the chop, sometimes not. it really doesnt matter at all. this plant looks a quite ready to me, but again i wouldnt do an "extended flush" that simply doesnt exist in hydro. 12hours is plenty 24 hours max. you're ready to chop any day now. hope this helps ! 🚀