The higher the degree of kelvin the less the output of light. It's a fact that even HID sellers are quick to admit. The best balance between the two is either 5300 or 6000. After that you trade the light output for the color. The wonderful thing about that is that cops have a higher tendency to be looking your way if you have purple lights (and it's not legal in some areas, if not all)
http://www.partsprovider.net/c....html
There is a chart to show you the relationship between color and degree kelvin (small writing thoug). Even though it only shows blue at 16k, notice the pic of the 12k, definately violet. But notice below the chart
The lower the K value, the higher the brightness level.