Stick to 6,500 K (daylight) for vegging and 2,700 K (soft-white or warm-white) for flowering. Full spectrum bulbs waste too much of thier energy putting out "lumins for humans" instead of good PAR light for plants!!!
Our (human) eyes are more sensitive in the Green and Yellow bands of the color spectrum - so naturally, Green and Yellow light registers really high on a "Lumin Meter". The problem is that Green and Yellow light is just about as useless as tits on a Nun - as far as photosynthesis is concerned.
On the other hand - Blue and Red light produce a more modest amount of lumins, but the plants eat up Blue and Red light - Big Time!!!
The point is - don't waste your money on CFL's that look brighter; spend your money wisely on CFL's that produce more photosynthetically active radiation(PAR light). Good luck!
Like jmiller said - you can run one 2,700 K (warm) to every three 6,500 K (daylight) CFL's for veg, then switch to one 6,500 K to every three 2,700 K for flowering. All the research I've done shows that this is beneficial.