In 1922, the Bauhaus apprentice Peter Keler, who was just 20 years old at the time, was inspired by his teacher Wassily Kandinsky to design the so-called Bauhaus cradle. This utilises the primary colours of yellow, red and blue and the triangle, square and circle forms that Kandinsky assigned to each of these respectively. The cradle was presented at the 1923 exhibition at the Haus am Horn.
Schulz, Bernhard (2009): “The Wonderful Furniture. Peter Keler’s Cradle” in: Bauhaus: A Conceptual Model, publ. by Bauhaus-Archiv Berlin / Museum für Gestaltung, Stiftung Bauhaus Dessau and Klassik Stiftung Weimar, Ostfildern: Hatje Cantz, p. 119ff.