Alan wrote:

My local electrical wholesaler had no old colours left when I tried but B&Q
had plenty.

My local B&Q branches had all previously run down their cable stock and
put up signs saying they would be replaced with a new range in due
course. Today I noticed they were well stocked again (full reels as well
as the expensive off-cuts!) and I had a look expecting it to be
harmonised colours, but it wasn't ...