Here's your old thread: Re: Preserving File/Folder Colours across drives.
Main two things:
[ul][li]Turn on Preferences / Favorites and Recent / Labels / Automatically store labels in the file system if possible (note that it only affects new labels)
[/li]
[li]Turn on Preferences / File Operations / Copy Attributes / Copy metadata (comments, keywords, etc) (note that this will slow down file copies slightly, when copying a large number of files)[/li][/ul]
That's it, unless you do something unusual like override either setting via command arguments, but you'd have to do that explicitly and with some kind of purpose, so you'd know if you were doing that.
Both settings are preserved when you upgrade from 11 to 12 so nothing should have changed if the new version was installed over the old config.