Henri Matisse painting of his studio (perhaps better than a color photo?) by Damian Elwes - he has a wonderful series of "Artist Studio" paintings!
Matisse color schemes in pie chart form by Arthur Buxton
Matisse Painting from his Sick Bed if Luke was this old and bedridden, or even…
Henri Matisse - La Musique, 1939 at Albright-Knox Art Gallery Buffalo New York