Why think about integrating Redshift [1] into KDE?

Because KDE could provide more pleasant experience by optimizing screen colors to match day time, to reduce eyes strain. Very nicely it's very nicely presented here [2].

How could it be done?

I would suggest to integrate Redshift directly into settings and allow users set day & night colors. Also offer possibility to read current location (or enter it manually) to figure out, when sun goes down.
Also allow possibility to disable Redshift and return original gamma and red value, in case when it's manipulated with photographic material (webdesign etc.) or battery is at critical level.

Inspiration could be taken from CyanogenMod 12+ systems, where this feature is presented as LiveDisplay.

Also when considering this feature, please try Redshift or some similar program at least 5 minutes, before eyes get used to different color. After while you'll see eyes adapt to new default "white" and calibrate accordingly.

[1] http://jonls.dk/redshift/
[2] https://play.google.com/store/apps/details?id=com.urbandroid.lux&hl=en