The best way to calibrate a display device would be by using a colorimeter which precisely measures the color a device outputs, but when you don’t have one of these at hand you’d still like to have more accurate colors, which is where the EDID cames in place.
EDID is a chunk of data that most modern display devices provide that give us information about the monitor’s model, make, size and even about colors! The colord-kde implementation already makes use of all this info to provide information about which display device you are dealing with, and now it also creates a self-calibration file (ICC) that is automatically loaded when the kded process is started (or when you plug your monitor).

+1 Feature
Totally awesome! Love what you’re doing and improving in KDE.
Hope you do get the finish (or reassign) the work on the printer applets 😉
We are trying to setup a GSoC for print-manager, but if that does not happen I’ll try to finish some missing bits…
Totally great! This was the missing piece after digikam, showfoto, gwenview dolphin and gimp!
Just some clearing about confused terms.
Calibration is not the same like colorimetric characterisation. ICC profiles are first hand about colorimetric characterisation. EDID contains very basic colorimetric information like primaries and white point, which rudimentary can characterise a screen.
But from EDID generated profiles certainly do not have any calibration curves. So apps to use a from EDID generated on the fly ICC profile are limited to ICC supporting ones. These among others are digikam and gimp. At the moment certainly not gwenview and dolphin.