There really is not much said on conditions other then heat...

Real quick one thing I found to worl miracles is Insta Green from Gro Tek.. $14.00 Ltr

If they are flowering I would not use High high Nitrogen...

If you really want to fix it we need all Nutes,PH,Strain,veg,Flower,ect...

IMO if they are in Veg and you want them green try that produst with in 2 days they change it is a Miracle Product IMO..;.

Good Luck To Your Friend