Possible Clues:

• Co-founder of the avant-garde Blue Four
• 'Heroic Roses' painter
• Painter Paul whose work was labeled 'degenerate' by the Nazis
• Friend of Kandinsky
• Whimsical Swiss artist
• 'Pastorale' painter Paul
• ''The Golden Fish'' artist
• Swiss expressionist Paul
• MoMA's 'Cat and Bird,' for one
• "Castle and Sun" painter Paul