Yellowing but healthy looking

I have my 6 girls that all look great except they are yellowing pretty good. My temps are warmer with the lights off than on , and i've heard this will yellow them quickly.

any thoughts?

im not sure but i think you got it backwards. if your night temps are higher than day temps you could cause a problem. my last grow i ran my lights at night cause it was so hot that i couldnt run them in the day. so my lights off temps ran higher than when the lights were on. from my understanding you should at least have a 10 degree f drop in temp when your lights go out. plants do some things when the lights go out like break down certain things and i guess cooler tmps help them do that better. there a thread here somewhere, some dude did sounded like he knows his shit