Van Gogh produced this drawing in Auvers in May 1890, on one of his first days in the village. He experimented in this work, and also in Cottages with Thatched Roofs, drawn in the same period, with various tints of blue, ranging from deep dark blue to watery light blue. As a contrasting accent he included a couple of bright orange roofs, that have now faded to reddish-brown. This work harks back to Van Gogh’s color experiments in drawings from his Paris period from early 1887 and also to several still lifes produced in Saint-Remy, in some of which the flowers form a simultaneous contrast with the background and in others a complementary contrast. Van Gogh produced more than 70 paintings in Auvers and only a small number of large, ambitious drawings, including this work in oil and watercolor. He began by laying out an extensive under-drawing in pencil, then filled in the sky with watercolor, leaving some areas blank for the white clouds... (http://www.tfsimon.com/auvers-sur-oise.html