Actually, although the warm white (+/-3000K) bulb looks 'redder' to you, it has a limited spectrum, while a cool white (3600 - 5000K) has more , and a daylight bulb (5000 - 6500K) has the most usable light for a flowering plant.

added on edit...
Why not use both?
psteve Reviewed by psteve on . Warm or Cool CFL? hello, i've got 2 kinds of CFL, one is White Light and on is Red light (not really Red but kinda) which is good for vegetation and which is good for flowering please? thanks!!! Rating: 5