I just bought a few "soft white" bulbs. The 42w ones are 2700k, as it says it on the base of the bulb. The 23w ones dont say anything about the spectrum but emit a much more bluish light. Yet both bulbs are "soft white". I cant figure it out. All I know is I have a bunch of 23w that I will use for veg and then click on the 42w 2700k when it comes time to flower. I am almost done building my setup, I will post pics when done.