BY Ernie Smith

The History of TV Color Bars, One of the First Electronic Graphics Ever Made

You don’t know Norbert D. Larky and David D. Holmes, but you’ve seen their work thousands of times. It’s existed in the brains of people who left the TV on an obscure cable channel in the middle of the night, the kind that doesn’t have 24 hours of content to fill their day.

You know the one, with the bright color bars that are hard to miss. It’s probably the most widely recognized, but test patterns like it have been a key element of television almost since the beginning. Read on to learn how we got them, and what they do.

These test bars, throughout their evolutions—with the most recent occurring in 2002 to account for the HDTV switch—remain important in the television industry, as they allow engineers to adjust color schemes to correctly match what’s on the screen and modify accordingly.

Before those color bars, a wide variety of different black-and-white images were used, most notably the “Indian head” graphic created by RCA in 1938, which became the first popular test image of the era.

Early televisions needed much more in the way of constant tuning, which meant that guidelines that helped owners test for the curve of the picture, the overall focus, the shading, and for interlacing were necessary.

During the early television era, this image showed up multiple times a day on some channels, along with an accompanying sine wave tone, which generally blared at a 1kHz frequency. (You’ve assuredly heard this dull blare many times in your life.)

Over time, color bars became even more familiar to TV viewers than the black and white equivalents. (Probably a good thing, as the black-and-white test pattern used a stereotypical image of Native Americans.)

Beyond its technical reasons for existence—initially, it was used for calibration in early color televisions, and is today used as a way to ensure chroma and luminance levels in modern screens of all types—it became a pop culture icon of its own.

Outside of North America, a highly complex PAL variant developed by the electronics company Philips in the mid-1960s has frequently appeared on television in different parts of the world over the years.

Over the years, the color bar test pattern has evolved multiple times to cover different color schemes. The exact sequence of color bars evolved from its first appearance in 1954— the bottom bars, a small part of the test sequence today, once took up more than half of the screen.

The most well-known design for the color bars, set by the Society of Motion Picture and Television Engineers in 1978 and updated in 1990, uses three rows of bars.

The result is that you can calibrate screens consistently and perfectly across the board—something that still matters in the world of video production, even if our modern TV sets need it less.

if you go digging far enough on YouTube, you can find examples of test patterns being used by major networks, some of which differ greatly from the standard styles you’re used to.

But those color-bar variants from CBS and NBC are nothing compared to what you can find on Netflix. Netflix, despite having no traditional broadcast component, has numerous test signals openly hanging out on its platforms, and they are fascinating.

The color bar design, more complex than it seems, is so utterly pervasive in modern life that we kind of ignore it’s there.

Color bars have certainly changed—they kind of had to, given the fact that our screen sizes changed—but they’ve remained persistent, not just to test image quality, but as an iconic part of television all its own.

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