For the ribbon, selecting payment status == paid in full will treat underpaid and overpaid bookings the same.
I noticed this on a direct booking where I accepted a $100 security deposit, which turned the booking to 'overpaid' but it shows the same kind of shading as underpaid.
Not a big deal I suppose.
Yep, security deposits are a bit of a strange beast right now as they're not recorded normally in the charges. We've got a planned overhaul there to fix some of these things.