I don’t think so either, I will probably replace this one by Apple. Have been to a local reseller to compare, there was a difference but very slightly, not very noticable though.
Compared to a 250 dollar crappy Samsung phone from work, you definitely see a very noticable yellow/orange tint in the 12 Minis display (truetone, colors and nightshift off). Not worth what we paid for it in my opinion.
EDIT: Update 26-11-20: Got a replacement. This one has the same issue :/. Using accessibility>display>colorfilters until Apple fixes it with a possible software update, seeing the high probability every phone has the same issue, and it not being device specific.
Please if you encounter the same issue with your iPhone 12 Mini, send feedback to Apple using the official feedback form
here.
The lockscreen buttons not working was also fixed by them using this form.