The stitching on balls used in Major League Baseball is red.
A regulation baseball has a white leather or synthetic cover made from two roughly figure-eight-shaped pieces. They are sewn together with red thread, creating the familiar raised seams that curve around the ball. The color is not merely decorative: the seams are an essential part of how pitchers control the ball.
A regulation baseball has 108 stitches. As the ball spins through the air, those raised seams alter airflow and drag. Pitchers exploit that effect to produce fastballs, curveballs, sliders, sinkers, cutters, and other pitches. The orientation and rotation of the seams can change how the ball moves after it leaves the hand.
The answer refers to the baseball itself, not the stitching on player uniforms or team equipment. Professional baseballs have also changed in materials over time, with synthetic covers appearing in some lower-quality or non-major-league balls. MLB baseballs remain associated with white covers and red stitching under the sport’s official specifications.