its all dependant on the company they are all slightly different. i sell them and the xenon kits i have are very bright. the lower the number the brighter they are, i have down to 4000K. the higher number the deeper the color, more blue. i also hae purple, pink, yellow and green. pm fpr prices i'd be poor than happy to help you out. i use 8000k on my car. they're fairly blue but still very bright.