Any idea how I can get that same functionality?
This must be a simple private mod. Everybody seems to do his own since that functionality is lacking from the client. But unless you are in the position to make changes to the UI yourself, I fear you're out of luck there.
Your best bet than is to get the ear of a Dev
I personally use some color-coding with 3 colors: green for good stuff, orange for stuff to grab at least, red for cursed or other useless things, all the rest stays plain. But I never actually cared to nail down my rules to proper loot. It's more a help to identify stuff worth grabbing on public corpses
