Going into the service menu will reset HDMI UHD Color to off, the Samsung light effect and all picture settings, it will not reset the CAL-DAY and CAL-NIGHT settings if you already have them unlocked.
Here is how to activate CAL-DAY and CAL-NIGHT settings
1) Download the IR service remote to an android phone or tablet:
https://sameapk.com/service-remote-control/
2) Power on your tv and select tv as the source
3) Boot up the ir remote on your android device
4) point the android device to the tv and tap the S1 followed by the S2 button. Wait a couple of seconds
5) Your tv should boot up the service mode, from here you can use your original tv remote.
6) Go down to SVC and select it
7) Go down to Other Setting and select it
8) Go down to Expert and select it
9) Press right on N/D ADJ to switch from OFF to ON ( You might need to press right a couple of times for the tv to register it)
10) Press return on your remote to go all the way back to the beginning ( about 3-4 clicks)
11) Power off the tv with the remote and then power on again after a couple of seconds. Now give the tv about 30 seconds to load everything up. You should now have both settings unlocked.