18 Muster für Wandanstrich [18 patterns for wall paint] was drafted for the City Planning Authority of Rotterdam. For the redesign of the existing complex comprising three buildings, Maria Eichhorn designed a color concept to link the separate architectural structures of each building. The natural stone walls of the biggest house were her starting point. Using a color scale, the first floor was painted red and the following floors were to be kept in the relevant complementary colors or combination colors, so that a ride with the elevator would encompass the entire scale. The floors in the other buildings were to be painted using the same pattern. The cards available in the box illustrate the color concept.