All of them, including McCartney, refused to comment on their allegiance throughout their career. I saw an interview 4 or 5 years ago with Macca where he still wouldn't comment on whether he was red or blue, saying he supported both!
Lennon was raised as an Anglican, Macca had one parent from each denomination, was baptised Catholic but raised non-denominationally and Harrison was a Catholic.
Generally Catholics support Liverpool, Protestants Everton, but I've not idea whether this was the case with the Beatles.
Albert Stubbins (former Liverpool player) appears on the sleeve of 'Sgt. Pepper's', reportedly as he was Lennon's father's favourite player.
Where this places Lennon's cry of "Matt Busby!" on 'Dig It', ('Let It Be') is anybody's guess...
In the movie 'Backbeat', which recounts the early days of The Fabs, Stu Sutcliffe (erstwhile Beatles' bassist and Lennon's best friend) is a Liverpool supporter, but whether this is relevant I can't say.
Really? I apologise - I don't really know or care much about football, but I had understood that where you had a red and a blue team, the red were always the Catholic team, and blue the protestants.
All a load of bigotted c-rap whatever way around it happens!