I found this posted at
http://boards.cannabis.com/showthrea...t=10956&page=2

From The Cannabis Bible by Greg Green:

CTT in Kelvin (K)/ Light Color/ Effect/

5000 to 8000/ Deep blue/ Encourages excellent leaf and stem growth.

4000 to 5000 / Light blue/ Encourages good leaf and
stem growth.

4000/ Neutral white/ Promotes normal growth.

3700 to 4000/ Warm neutral/ Promotes rapid growth.

3000 to 37000/ Warmer yellow neutral/ Highly active
photosynthesis for all stages of growth.

1500 to 3000/ Hot orange or red/ Promotes flowering.