im currently debating which cfls are best.. if you go onto the new posts and check beal's m15 auto assasin grow you will see he is using just 14000k lights, his grow is looking sweet.. alot of people say to use just blue 6400k.. so my theory now is that the higher k rating the better, but i can guarantee this is true im just going by what i have seen.. in my cfl light i have, 125w 2700k 125w 6400k and a 250w 14000k.. i havent used my 14000k light yet as im currently setting up..
if your getting both bulbs have them on at the same time, maybe the first week just use the blue 6400k then week 2-3 put the red in too... my last grow i started with a 125w 6400k + 2700k and they worked perfectly..
probably not the best answer but i feel we still have a lot to learn with cfl's.. get a 14000k too and have all 3 colours !!!