The higher the K or Kelvin temp (5000K, 7000K) the lower the light and more color. Stay withing the 5000K-6000K, that will give you a white/blue color.
The lower the K the more light there is.
My old bulbs were Hiper Plazma Xenon (made by Hiper Industries) 85/80watt and they were very bright. I found the box and there 4000K and they were pretty blue. Make sure when you change the bulbs adjust you headlights (screw on top). Thats how i got the most out of my hiperwhites. Once i got them in i adjusted them slightly higher then normal so that light up the road as far as they could go. Never had any problems with people flashing me either