"Blue on black
Tears on a river
Push on a shove and it don't mean much...
Joker on Jack
Match on a Fire
Cold on Ice as a dead man's touch
Whisper on a scream
Doesn't Change a thing.."

The light of CFLs when compared to ambient outdoor light isn't going to be worth the trouble of supplementing it, and the presence of a light outdoors is suspicious in and of itself. Why can't you put your plants somewhere sunnier, or bend shrubbery out of the way to break the shade? This is why it is important to consider the placement of outdoor plants before they are set in the ground.

You want the BLUEST light you can find for veg, and redder light for flowering your 'plantz'.