[Wendy Cutler]

@Mike: I would prefer that the song title color applies to every place where a song appears in a list: Setlists, Songs, Collections...

@Wendy, Geoff: having a separate collection (or maybe a Genre) for separators seems more flexible to me than tweaking the title.
Learning to use filters is worth the effort. Applying stored filters is very flexible and convenient.
I have stored filters for eg.
preparing setlists: include Collection "Band A", include Collection "Separators", exclude Genre "XMas"
all "true" songs except christmas songs: exclude Genre "XMas", exclude Collection "Separators", exclude Collection "Tips+Tricks"

Thanks, @itsme. I would just tweak the title for a real song where I want to highlight it on the list for some reason, like practice this! Or remember to play it.
I'm so happy with my smilie prefix for separator names, I'm going to keep using that. They're all sorted to that "letter" of the alphabet.