aluminum Christmas tree color wheel

Those memorable posters from the late 1960s psychedelic era often used clashing primary colors to give the illusion of vibration. The works of artists such as Victor Moscoso, Gilbert Shelton, and Wes Wilson used this device often.

But the clashing colors had another feature ... to explore this, we must take a kitschy journey back to the early 1960s, and the aluminum Christmas tree. The artificial trees were colorless, reflective aluminum foil ... but also electrically conductive, so stringing the usual lights was hazardous. So for color interest, vendors sold color wheels along with the trees. These were spotlights mounted with a motor which rotated colored panes of plastic in front of the spotlight. As the color wheel rotated, the tree would gradually change colors.

These rotated slowly, about 2 to 5 rotations/minute, more or less. But the inventive folks who dabbled in light shows for concerts rigged them with faster motors, around 1 rotation/second, often with a variable resistor to change the speed to match a song's tempo. As a result, posters all around the concert venue would pulse dramatically.

The 60s period artwork is under copyright, so I have poster-ified photos of our Notorious Cat Boys as example subjects below. The color wheel effect is emulated with blue, red, green, and yellow transparent overlays that cycle twice per second. Click the links below the images to see the effect. Click the "STOP" links when it starts to drive you nuts. And please note that in the 1960s concert venues, there was a whole lot of sensory input going on, and one tended not to dwell too long on the posters.