Usually artists fade the value and intensity of colors in a painting as objects recede.
However in this Manet painting the light colors in the back-center lead the viewer’s eye through the painting, from the cloths in the foreground, to the seated picnickers middle ground, to the bright background.
The composition is framed, by the dark colors on the sides. Overall the colors are bright, the nudes being the brightest, symbolically and visually.
There are not dramatic lighting effects or heavy shadows. Chiaroscuro effects of suggesting volume through light/dark contrasts on the figures is minimalized.
