You confused me at first, but I guess you're thinking of the Tardis - that's a police box, not a phone box! British phone boxes are always red, I think.
The classic ones are red, there are (were) ones installed in the 80s-2000s which are mostly glass and grey aluminium (IIRC) that had a the BT logo on the side.
The classic red ones are more typically associated with smaller villages etc nowadays, often turned into mini community libraries or have been retrofitted to carry defibs. Some towns still have them but very few still function.
Also for context about the original picture, I believe it's a reclamation yard type of thing, you can often buy old/vintage building materials/farm equipment/utilities etc at them for a somewhat inflated price
Yea police boxes were already being phased out when the first episodes of Doctor Who aired as UK cops started getting radios. Don't think you'd have any chance of finding one now.
There are still a few of those red boxes in parts of the fairly big town I'm from but yea a lot were replaced with the black and stainless steel ones in the 1990s and I don't think any of the ones left standing have actual phones in them anymore.