Jez, well said.
often the aircraft are 30+ years old with a paint job from the days when yellow and brown were de rigueur.
We had a PA28 with a red velvet interior and little curtains that you could draw for a little extra privacy in the back. There's a persistent rumour that someone once setup a "mile high club" service with that aircraft.
That aircraft was given a major overhaul over the last few weeks. New paint job but also a new grey leather interior.