Test Pattern History: How Color Bars Became a TV Staple (2020)

Color bars, now an enduring television image, began as a practical tool for calibrating color displays. Engineers Norbert D. Larky and David D. Holmes filed a patent for a color test-pattern generator in 1951; it was granted in 1956. Their work grew out of an era when televisions needed frequent adjustment for focus, shading, picture shape, and other problems. Earlier stations used black-and-white patterns, especially RCA’s 1938 “Indian head” image. That picture became a familiar broadcast feature, but its generic, stereotyped portrayal of a Native American also reflected the limited and distorted representation of Indigenous people in popular media.

The color bars’ layout changed over time, with standards evolving to serve increasingly precise technical needs. The widely recognized design has a top row of color fields for checking brightness and color, a narrow middle row that helps technicians compare hues and saturation objectively, and a bottom row with signals for setting black levels and checking the transmission. Although modern televisions generally need less routine tuning, the pattern remains useful in video production and has become a cultural icon, appearing in music and entertainment. The account also notes that test patterns were among the earliest electronically generated screen graphics and that Netflix hosts unusual test programming, showing how the form has outlived its original broadcast role.