When I installed my first HID's in one of my rigs, I was told to go with 6000K, and that they were the "brightest". I hated the damn things. They turned the snow on the road blue, hid black ice and gave me a friggin headache. I then moved to 4300K and everything looked clear, no blue or yellow tint whatsoever.
Rick - that would be much appreciated. I need to order some more lights, and if these warm whites that I have now are too yellow, I'll send them back and get cool white. The only reason I bought the warm white was because the cabinet maker I spoke to told me the warm white looked more natural and the cool white were pretty bright and better suited for task lights, verse ambient / accent.
