I started off with 20Ks, and I really like the color, though I thought they were a tad dark (though they were used bulbs and a tad worn out but still). Then I got 10Ks to replace them, and I thought the color was a bit yellowish at first in comparison until I got used to them. Talk about sparkle, though! Then I thought that next time around I would try 14Ks as a compromise.
I got really good growth under the 10Ks compared to the 20Ks, also. If you're not worried so much about growth and just really want to enjoy the color, go with a bluer light. You can always add white VHOs to help balance out the 20Ks to your liking. Or get the 10Ks and add more blue actinics.