Well it all depends on the brand. Of course the 12k bulb is going to have a little bit blue tint than the 10k bulb. You'll just have to look at the spectrum of each bulb to see which one you like the most. What some do is get a lower kelvin bulb (10k)and get an acintic bulb to give it the blue'er look. Many times the lower the kelvin the better the spectrum but it also gives it a yellow tint look.