When you arrive the painter will remark that his paint is missing, search the area he points to first then follow the path to the western most portion of the quest circle and use your Witcher Senses. He'll ask you to follow him by horseback so hop on Roach and follow the painter to the hill top he specifies to update your quest again. He'll ask you to meet him by the western castle gates at noon, go to the location specified and meditate until noon. This quest begins by speaking with the Painter (pictured above) who is in the central portion of the town of Beauclair. A Portrait of the Witcher as an Old Man - Toussaint (Blood and Wine)