The main reason you want to use different colors of light is that blue keeps your stems from growing too long, which you want during vegetation to keep your plants somewhat compact. However, when you start flowering, you want your plants to stretch out and leave a lot of room for buds on their stems, which redder light will do.

If you're growing with just CFLs, you're probably not going to get massive yields anyway, and you want your plants to stay short, so you can use more blue light. However, try and alternate them so that your plants aren't getting different colors of light from different sides. This can make plants twist in funny ways, and if this is happening, then switch to just one color of bulb.