At least 6,000 homes in the UK have a black & white TV licence

"The BBC’s Annual Report & Accounts states that at least 6000 homes are viewing TV on monochrome licences.  The colour TV licence was introduced as a £5 supplementary fee to the – then – £5 monochrome licence in January 1968.
The fee for a monochrome licence (for 2017) was just £49. This has risen to £49.50 for 2018."

Source:  Advanced Television, 12th July 2018