What if you went to this place at night and somewhere amongst the sea of red boxes a telephone started to ring?
Pick it up. It’s for you.
What if you found a blue one? And it was bigger in the inside?
What if these were the TARDIS’ of all the other time lords? What if the Doctor’s TARDIS was a blue police box because he wanted to stand out?
Or what if when a TARDIS dies it turns red? Everything changes once life has left. Bodies decay. Stars explode. What if a TARDIS becomes an ordinary Telephone Box?
Or these are all the attempts of past companions to make their own TARDIS. To try and chase their Doctor among the stars