Red and blue as in soft white vs. daylight or red and blue as in colored glass or filter? Different spectrum bulbs are useful depending on the stage of growth the plant is in but filtered light is not.
Agreed. the difference is using daylight or 5000k to veg with and soft white or 3000k to flower with as apposed to standard cfls is you will be giving your plant the light waves it needs most at these grow stages. The others will work. Just not as well.
Bulbs that are covered with material to change the color you see with your eyes do not do your plant any good.
Ahh, Leds are pure light, I use them to veg with. I have tried them to flower and no dice. Small airy buds. You need something bigger. Vegging? Added to t5 its the best I have ever used.