I was about to jump on that, but it's basically correct. However,
you'd want the backlight to be "reasonably close", so you didn't
have to push any channel to its limits of adjustment.

... not really. The backlight on this monitor is far removed from the
colour temp its operating at, and all is well. When its far removed it
does affect contrast ratio a bit.

I have to disagree. Suppose the backlight doesn't produce sufficient blue
for the desired color temperature. You can compensate by displaying the blue
pixels at a higher luminance level. But you can't go higher than 100% -- the
lightest (highest) level the LCD can transmit. That level might not be
enough to match the green and red levels.

A roughly similar situation occurs with color-negative film. If you expose
daylight-balanced film at 2800K, the blue layer might be unacceptably
underexposed, and no amount of additional blue-layer exposure during
printing will restore the lost shadow detail. Ditto for exposing 3200K film
under daylight, except the error is on the side of overexposure.

Simply stated, neither an LCD nor photographic film can display or record an
infinite brightness range.