Matilda

Hey, could it be that autumn colors are a good and normal sign that the plant now is progressing into flower maturity? Your buds already have a good size and all they'll need to do is producing some more trichomes and the ingredients of those , mostly from allocated resources of the elder leaves. If you fertilize when there is no need for any nutrient anymore (as not much new tissue will grow from a certain point), especially nitrogen, then you may interfere and interrupt the senescence programs that aid in allocating resources from unneeded organs into flowers for their final development. Chlorophyll degradation should not be inhibited but be promoted for better quality. I would not fertilize at all and start flushing. Furthermore, thc, cannabinoids and terpenes are carbon based, carbons that may be recycled from older and degenerating tissue.