@knowmad. You CAN do whatever you want. If it were me though, I would give your plants some sort of lights out period. As hard as we try, we very rarely beat mother nature at her own game. So why not try to replicate her as closely as possible?
If your boss said "I need more production out of you Knowmad! You're going to start pulling 24 hour shifts from now on!" What do you think would happen (aside from you telling him to FUCK OFF & getting fired)? If you tried it, you might be able to pull it off for what, 2 days? Then what would you want to do? REST?!?! Why are plants any different? We're all living creatures. My advice would be to give her 18/6, but if you just HAVE to have longer light schedule, try 20/4 or 22/2. I know I've seen people's grows that turn out just fine this way... it just doesn't seem right to me that we can expect plants to go non-stop & still have the same quality of output/production as they would given a decent break every evening.
As far as your lighting question, YES, you can leave it under the 6500k bulbs as long as you want. When you think about CFL's though, try to compare them to HID lighting. It is pretty well accepted that MH (metal halide) bulbs are used during Veg... These are most similar to your 6500k "bright white" colored bulbs. Most HID growers switch to HPS (high pressure sodium) bulbs when it's time to flower... these are most like your 2700k-3000k "red" colored bulbs. On the other hand though, most HID growers will agree that if they had to choose 1 bulb over the other, they would grow all the way through with their HPS bulb. The reasoning is, the MH will do wonders for veg, and will be "ok", at best, during flower. HPS will do "ok" during veg, but will rock the fuck out of our plants when we flower. So - if you have to make a sacrifice, most would rather do it during the veg cycle - as opposed to using sub-par lighting during the flowering stage.
If I was using CFL's, I would not want to make any sacrifices when it came to appropriate spectrum. I would want 6500K during veg, and then switch to 2700k during flower. It's your call though. They're your plants. Whatever you decide, just make sure you do your research and know how to get the most out of what you're using. Good luck & keep it green buddy. How bout some pictures?