Hugh, there is a vast range of colour variations of Feral Pigeons, white, brown, blue, grey and any mixture of hose colours!
they do not make good eating also they are carriers of a whole host of avian diseases, they are commonly called flying rats. Descended from the. Rock Dove. A menace to buildings because of the pigeon crap which eventually coats the buildings, if not cleaned off! Pest control companies make a fortune from clearing them out. The weapon of choice is an air rifle!
Now the Wood Pigeons on the other hand don’t make the mess and are very good to eat!