After serving up three nail polish collections inspired by world tennis tournaments for OPI, Serena Williams is back with her fourth and final lacquer launch—Glam Slam US! The lineup includes two new colors, a fiery red Love is a Racket and a metallic Pros & Bronze (shown inset). "Whether worn alone or layered for a golden glow, the two shades have rich hues that make a perfect transition from summer to fall," Williams said. The new polishes are in stores now ($15 for a set of two), just in time for the US Open! Click through the gallery to see the new colors, and all of Serena's Glam Slam nail polishes for OPI.