Change temperature values of Night Light

The screen of my laptop (Dell XPS 15) is rather blue.

An alternative could be to set the preinstalled D50 color profile to the laptop screen on the standard Settings app's Color sidebar item. (Monitor calibration misery is not needed; the D50 profile is available from the Add profile dialog).

color profile settings UI screenshot

This in itself compensates the blue-ness of the LCD to a really decent level.

It is not timed or periodic, it's on all the time. This could be your "day-time" compensation.

The night-light, when it gets turned on, will add its shift on top of this; they play nicely together.