Originally Posted by KPC1.8TQuat
If the kit uses 50w/55w ballasts and 35w bulbs, yes the color will be lower in K. The output will also not be as bright, and the heat production from the bulb is greater, and longevity is redced. As from fitch303's experience with DDM, that is exactly the case. 5000k should not be yellow at all, but it is because DDM supplies mismatched 50w ballasts and 35w bulbs (sold as "55w").
HOWEVER, when proper 55w bulbs are used with 55w ballasts, the color for a 55w vs. a 35w kit is the same. Heat production is lower, the output is that much brighter, and the bulbs longevity is not affected. 5000k should be pure white, if anything leaning ever so slightly to the blue side of the correlated spectrum.