In Paris, Vincent discovered that his style was too dark. For a year, he turned his attention to painting still lifes for the study of color. In many of his drawings in 1887 color played an important role. This showed innovation in his technique and style of drawing. Now he was doing real watercolors. These drawings are transparent and colorful with nice complementary color contrasts. (Google translated from http://geschiedenisenkunst.com/geschiedenis-tekenkunst/?pg=4)