if it needs to go longer, better start feeding it again... the fist picture may be senescence or night time temperatures - looks like autumn colos coming in, but a lack of nutes could cause something similar too, i guess? either way..
flushing has no real positive impact on the buds despite common thought. it doesn't reduce minerals (absurd... it's not a f'n sponge) and doesn't improve taste based on some blind taste tests. So, no worries.
if you want to flush cause it makes you feel all war inside... or maybe just don't want to mix nutes at end, go for it. you can always stop feeding again, and have no fear the interruption of the 'end harvest flush' will have virtually no discernable impact on the results.
even trichomes coloration is slightly misrepresented by the peanut gallery. clear is not absent of thc and cloudy is actually the beginning of degradation. Amber is further along in that process. pistil coloration and retraction is another good observance to keep you on time with flush... density of buds is another (though you don't want to squeeze often, once or twice near end on 1 or 2 buds is no problem.) 3 phyical traits to watch. trichomes are not 100percent perfect for this decision, but they are probably the best of the 3.