“Public images: these are objects that have a firm place in the polis – in the agora; unique objects that match the scale of the city (or landscape). [ … ] The Farb Zeit Turm [Color Time Tower] for Westdeutscher Rundfunk [West German Broadcasting] in Cologne [is] a kinetic color pylon, which is 25 meters high and consists of 60 rotatable elements. The cross-section of each element is triangular and contains three colors which are assigned to different cycles. Controlled by a mini-computer, the elements are turned 60° per signal. A total of 60 different programs run, each lasting one minute.

The effect: when the elements rotate, the color cycles mix; the colored surface is set in continual motion which is accentuated differently."

[Serge Stauffer, “100 Fragen an Karl Gerstner,” in: Freunde + Freunde, Friends + Fruend. Karl Gerstner, Diter Rot, Daniel Spoerri, Andre Thomkins und Freunde, exhib. cat., Kunsthalle Bern, Kunsthalle Düsseldorf, Edition Hansjörg Mayer, Stuttgart, 1969, n. p.; translated from the German.]

Source: [Rosen, 2011]