We had a hard time calibrating our Toshiba 50L1400U LED TV. Even at the end, it was far from perfect. We decreased the contrast setting all the way to 25 to have a more stable gamma curve.
We turned off most settings in order to get a natural picture. We never do a colorspace calibration, so we also turned off ColorMaster (we only do a 2-point grayscale calibration in our reviews).
The color temperature closest to 6500K was Warm. Unfortunately, only a 1 point grayscale option is available; the colors change a bit based on their luminosity.