Plant getting lighter — deficiency or excess?

Ca,Mg excess and lockouts check ur Ca/Mg ppm don't add any for a week or flush it

It definitely doesn't look like a nutrient lockout, especially since you've fertilized relatively little :) The ladies just need significantly more nutrients during flowering and for the stretch, even if they are autos... The need for N decreases significantly, while the need for P & K increases a lot. Try to carefully add some and see how the leaf green changes... for a quick fix, prepare a foliar spray... Cal Mag is always good, but not too much since an excess can block the uptake of K, which isn't the case for you right now, as it would show differently... Your ladies are definitely lacking phosphorus! Cheers

Hi, yeah at first glance it could be a slight nutrient lockout due to the wrong pH level in the soil, caused by too much fertilizer. Check your runoff and measure the pH and EC levels. The pH should be between 5.8 and 6.5; if it's outside that range, you need to adjust it. Otherwise, your plants won't get any nutrients. The EC should be below 2; otherwise, there are too many salts in the soil. If that's the case, give them just water with corrected pH once or twice. That’s what I would do first. If all that is okay, then it could also be an iron deficiency, which can turn your leaves light green until they eventually become yellow and die.