Robert Motherwell 羅伯特·馬瑟韋爾 (1915-1991) Study in Watercolour No.6 (In Green and Blue) 水彩研究6號（綠與藍), 1969 Acrylic, watercolour, and graphite on paper 紙面丙烯、水彩、石墨 77.5 x 55.9 cm (30 1_2 x 22 in.)