A viewer in Chicago told Popular Photography magazine (July 1968), "I saw pink! It knocked me for a loop...the letters S-Q-U-I-R-T looked greenish or light turquoise...and it kept up for maybe 10 seconds." (Meanwhile a viewer in San Francisco claimed he didn't see anything colorful.)
The burst of color was not "living color" (as NBC frequently touted in the 1960s), but something called "subjective color." The process was developed by James F. Butterfield of Color-Tel, a corporation founded in Los Angeles in early 1966. It gave the illusion of color by pulsating white light in a particular sequence for each color with a rotating device attached to a regular black and white TV camera lens. Butterfield had found in his many years of research that the human brain perceives colors through complex electronic codes. Butterfield was able to figure out the individual codes for the colors red, green and blue, and by pulsating white light in predetermined patterns with the device on the camera lens, could induce the brain of the television viewer to perceive color. Beyond that, ordinary monochrome equipment could be used in filming or taping, broadcasting and viewing.
There were a few drawbacks. The images were nothing at all like true color TV. It didn't have the intensity or range of colors. As the technology currently stood, the effect could only be used on still images. The "subjective color" could only be seen in about one-fourth of the TV screen area, and, because it relied on flickering light, there was a lot of flickering. It was also found that some people could not perceive the colors at all, yet some people diagnosed as color-blind could see the colors.
Nonetheless, Popular Science, in its August 1968 issue, saw many possibilities for the technology, particularly for special effects. "Color will appear in cartoons, commercials and special presentations. Polka-dots on a clown's suit will be seen as red flashing dots. You'll see the designs and lettering on a cereal box in pulsating green and blue. A girl will plant a kiss on a boy's cheek--and a red lipstick print will appear on your screen."
Popular Electronics (October 1968) went on to report, "Right now, Color-Tel engineers are checking into the possibility of using electronic color for such things as color radar displays, color computer readouts, and perhaps even color sonar pictures. It may be true that, in its present stage of development, Butterfield's process is nothing but a scientific curiosity — however, 25 years ago, so was television."
Popular Science predicted, "You can expect color on your black-and-white TV by this fall ." But there was one giant flaw in that rosy prediction. By 1968, black-and-white TV was well on the way out. The vast majority of programming (outside of old movies and TV shows) were being broadcast in "living" color by then, and while most U.S. households still had black-and-white TV sets (color sets were big, bulky and expensive in those days), more and more homes were purchasing color television sets every year. Had James F. Butterfield perfected the process ten or fifteen years earlier, in the 1950s when 90 percent of television broadcasts were black and white, it might have had more of a serious impact.
Although James F. Butterfield had many patents to his credit before his death in 2013, it appears this experiment didn't go as far as the press of the time might have suggested it could. Color-Tel last renewed as a corporation in 1972, and we can not find any evidence of other "subjective color" broadcasts beyond the Squirt commercial.