Painting the Town Red is a phrase used to describe a night of wild and exciting activities. It usually involves going out to bars, clubs, and restaurants with friends and having a great time. It can also involve painting the town red with graffiti or other forms of art.
From Wikipedia
Painting is a visual art, characterized by the practice of applying paint, pigment, color, or other medium to a solid surface. The medium is commonly applied to the base with a brush. Other implements, such as palette knives, sponges, airbrushes, the artist's fingers, or even a dripping technique that uses gravity may be used. One who produces paintings is called a painter.