I was just doing a lot of reading on this, it turns out that LED grow lights are actually better for plants than the old fashioned ones. Plants grow 30% faster than under florescent plant lights.
The reason is because LED lights have more focused light, with more "usable" energy per bulb. It is also mostly outside of the visible lights spectrum (just like the sun) so even if it looks darker, it actually is brighter from the plant's POV.
Blue LED's are used for the vegetative state and red LED's help more during the blooming stages of a plant's life. The stability of the light also produces bigger blooms with fewer defects.
LED grow lights on the market are UBER expensive however, a few research papers mentioned that they are made with ordinary 100LM blue and red LED bulbs. This means you can get inexpensive light strips and use them as your plant lights.
Inf act, this is what some research labs do to cut costs.
I have a blue light I haven't been using because it was keeping me up at night, but I will turn it on now during the day.
One paper mentioned that the "purple" color can be balanced out by adding more green and white lights strictly for esthetics.
Coincidentally, cool white is almost as effective as florescent, but the light temperature is not quite right, so if you have high light plants you will want to add the blue and red.
I learned all this in the past three days reading numerous biology research papers and light spec sheets, wish I kept track of all the sources but I did not. Sorry!