Yeah I am just using a 4000 K LED shoplight and had one set of problems (fine for some greens, just not for tomatoes) and you can see this pic as well, with a lot of purple on the LED seedlings:
http://www.tomatoville.com/showpost....6&postcount=19
It sounds like you have the real deal for LED grow light and should be able to tweak it so they are getting all the spectrum they need... narrow band at 4000 and 6000 K doesn't seem good at all for the maters. And TinyTim tried out another one, said he had problems too.