,Your not complete write,it measures how intense the light is under these primary colors,and yes these are the best color ,lol,and purple is 1 color and is measured under Kelvin 10k....Solis Tek bulb ,Thanks...
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Best Ballast is these brand cause of longevity but most of of Total Harmonic Distortion ..The balance from ballast to bulb ,there is no distortion... meaning more power to bulb and longer life,not only that they make affordable kits...(As long as you buy from MBFERTS.COM) just professional...