A mix of light is good for your plants

[Lollipop]

I myself use a mix of M.H. and H.P.S. and go with 400 watt M.H. with standard magnetic ballast but then i add at begining of flower 600 watt lumitec digital ballast with Philips Green power HPS bulb and have found that this helps get more Psycoactive affect in Sativa Indica mixes. When my plants are young i give them T5 stip lighting as i find that this helps with tight internodes spacing so more bud sites happy days, anyway i hope this helps someone probaly not as i have comfused myself LMFAO

[Roofie]

I agree lollipop. In nature cannabis uses the sun which is a mixture of all the colours. I know that red and blue ends are the most important, but your plants will be able to use light of nearly every wavelength.

[Jeffinsidney]

I saw at lowes today GE plant and aquarium F40T12 floresent bulbs 1900 lms 40watts 90 cri/irc. what would the plant do in a 6X6 closet with those bulbs in on a light scedule as informed here.

[garylee]

I'm not sure but is that 1900 watt lumen number actually the Kelvin number? If it is go back to Lowes and look for something in the 5500-6500 K. The light you purchased would have a lot of deep red so it would promote stretching and make a tall gangly "big bird" looking plant. Also free is one thing but if you are purchasing then try and get T5 bulbs and fixtures. Much more energy efficient, more lumens for power consumed.

[Saturnalia]

He probably is referring to lumens. 40 Watts. 1900 Lumens. It's the cri number that is about the colour temp here.
Also, worth pointing out his post is from July 2014.