[TimoJ]

That makes sense, depending on your original input: I hope you tested with a picture. With kodi set to Full - the original value should come out - means if you have a full range RGB grey ramp: Black is 0. If your Black is already 16 - then it's clear that it gets 20 when you additionally enable Use Limited. Cause the 16 in full range is a dark grey, so in Limited it needs to be 20, cause if it was 16 there as well the original dark grey would now be black -> not what we want.

^^ This is true for pictures in full range. For Video (especially hw decoded ones) it's different.

 It was a full range picture, you can get it from here: https://www.cs.cmu.edu/afs/cs/project/se...mg1024.gif
I still think it's not shown correctly. Kodi GUI in limited mode is not mapping full range 16 to 20, it's mapping it to a lower than 16 value and makes it invisible.