In the past, the seams of baseballs used in the National League were black and blue. However, in the early 1990s, the American League Baseball authorities established the standard of using red waxed thread for the seams, which led other baseball manufacturers to follow suit.
Despite the color change, some stitching patterns from the past remain in modern baseballs. For example, the “8” shape stitching pattern and the shape of the finishing yarn are still present. This means that the stitching process and coloring of today’s baseballs still retain some of the aesthetics from the past.