One theory is that the phrase “paint the town red,” meaning to celebrate wildly, often with drinking involved, came from an incident in 1837. That’s when the Marquis of Waterford, known for his love of drink and mischief, took his friends on a wild night on the English town of Melton Mowbray. The night included vandalism on homes and public buildings, including painting a tollgate, the statue of a swan, and people’s doors red. They did compensate their victims later on, though.
Another, more American, possibility is that, during the Wild West era, men visited brothels, where they drank heavily, raised hell, and carried on activities the brothels were set up for. They did this so often that they were acting as though the whole town was one large red-light district.
If either is true (or both), the phrase grew out of men acting like, er, donkeys.