In 1921-22, architect C.R. de Boer built in his hometown of Drachten, among other things, a block of sixteen middle-class houses on Torenstraat and, opposite, an agricultural winter school. For these commissions, he enlisted the help of Theo van Doesburg, the founder of the magazine De Stijl. For the houses, Van Doesburg made far-reaching color designs for both the exterior and interior. In retrospect, the collaboration with De Boer was a turning point for Van Doesburg. He developed an entirely new idea about the relationship between the visual and the architectural. Van Doesburg spent most of this period in Weimar, where he tried to introduce his ideas at the Bauhaus. In the letters to De Boer published in this issue, this crucial period in the life of Van Doesburg and the evolution of his views on color in architecture can be followed almost step by step.