[manarth]

There has rarely (if ever) been a separate broadcast signal for B&W vs colour. Broadcasts began in B&W, over time upgraded to colour, but there wasn't a need to broadcast Channel <whatever> in B&W and broadcast the same channel in colour on a different frequency.

One single broadcast signal, and different capabilities of receivers.

[Xophmeister]

But surely B&W TVs only exist with analog tuners?

[manarth]

Oh, I misunderstood the point you were making.

I guess you _could_ have a modern digital receiver with SCART-out (if such a thing exists) to a B&W TV. This BBC article (2018) claims 7,000 people watching TV with a B&W licence – whether they were actually watching it in B&W is not known :-D

https://www.bbc.co.uk/news/business-46125741