While the mixed signage in the thread refers to the Metropolitan line part of Moorgate station, there's a similar mix going on in another part of Moorgate station, specifically the part that's the terminus for the Northern City line (https://en.wikipedia.org/wiki/Northern_City_Line).

It's very anachronistic in terms of London stations - its platform design (and that of most other stations on the subsurface part of the line) is still in the "Network South East" colours and fonts, which for reference hasn't technically existed as a concept since 1994. Just think - a colour scheme now 24 years out of date!

It's a line that isn't on the main Tube Map as it's technically part of the National Rail network and isn't run by Transport for London, even though if you wanted to travel from Moorgate direct to, say, Finsbury Park, the Tube Map would have you believe you need to change at Kings Cross.

(Though mostly this doesn't matter as the vast majority of passengers are commuters from the northern suburbs into the City anyway.)

There's a nice set of photos comparing old with new here, note especially how little it's changed and how unloved this part of the station looks compared with the TfL part. https://www.flickr.com/photos/60539035@N02/sets/721577011132...