@JackTheCat I'm old enough to remember when you rented your phone from BT. Any colour as long as it was green. Maybe beige if you really pushed for it.I hear there are illegal 3rd party cowboys who will replace your string for coloured versions.
I had a contentious planning application in for an extension to my cottage back in the 1980s and the local council's chief planning officer came round to see the situation for himself. Back in those days I had a trimphone (frightfully modern back then) and when the CPO needed to phone the council planning dept. to clarify something, he asked if he could use my phone - then which end of the handset he should talk into!
It's the only reason I remember having a trimphone is because that silly twat could figure out which end of the handset to speak into!