Almost looks like phosphorus deficiency with nitrogen burn...notnsure what your feeding it but yellow is usually lack of nitrogen or water, purple is lack of phosphorus. How often are you feeding your girls?and your slightly acidic in your soil. Some.plants run that way but most like ph of 6.5-6.8 . If your roots aren't happy than its reaction is generally extreme to nutes , heat , everything...This just started about 1 week ago, im 6 weeks into flowering, ph is 5.7-5.9 temp is 76 degrees lights are led full spec, nutes every other watering. Is it normal for leaves to do this during flowering or is something wrong???
Absolutely right.You may have just noticed but most of that started long ago
You may have drifted your PH at some point or caused nutrient lockouts by poor feeding watering practices
but that damage isn't sudden