I thought the White Balance pre-set (that would have been a better name sorry) has a certain influence on the saturation levels (so on the gamut). If you are unfortunate to pick the wrong setting, you could end up with undersaturated primaries or secondaries, which would be bad.
That having said, if you pick the wrong WB setting a second issue may arise: you may not have enough "range" to alter the R, G or B components and end up with not having enough range to get to neutral white (euh grey..). The Cool setting has waaaay to much Cyan(as you might expect) and my TV may not have enough range to counter that excess of Cyan. I'm aware of that.
This does not make the choice easier....
Warm has too much saturated green and cyan and has slightly undersaturated blue and magenta.
Normal has the same issues but does not suffer from undersaturated magenta.
Then again, warm does not have so many overbright primaries/secondaries.
Which begs the question. Do I pay more attention to the colour temperature (which will probably be less blueish with the Warm preset) or do I pay more attention to the fact that Normal has less undersaturated primaries. I only took the latter into account, and hence my choice for selecting Normal over Warm.
My gear: Panasonic TH-42PF11EK pro plasma display + TX-P55VT60E -- Iscan Duo video processor -- i1 display 3 colorimeter -- i1 pro 2 spectrometer