I am using soft white CFL's for veg and flower. Just switched to flower a few days ago when the plants were 25 days old. Here are pics at day 26 total, day 1 of flower. Yes there is some yellowing of leaves due to the lack of nutes. I have not given them any nutes yet, but will at the next watering.
Here they are at day 14 2 weeks:
I can ASSURE you it is not because of the spectrum of the CFL's as you can see
clearly in these pics they are doing fine with
soft white CFL's.
It looks to me you need better drainage in the soil. You need some perlite in your soil. Could possibly be root rot due to lack of drainage.