With no photos is difficult give advices, it can be natural fading of color with the fall and the lack of nutrients that u are searching if u flush and so it’s a good think, after the harvest you will cut off them.
otherwise if you are continuing to fertilize it is in shock from too many fertilizers and you have to rinse the soil so as not to smoke it.
Hope to be useful and comprensive ✌️🏽💪🏼