Painted in 1973, Sonia Delaunay's oil on canvas, Rythme Couleur (Color rythm), strikingly illustrates the artist's work and its application to the theory of Simultaneism in painting.

This is also what the poet and writer Guillaume Apollinaire called Orphism, an avant-garde movement practiced by the Delaunays, based on initially figurative subjects combined with the mastery of light created through color.

Modernity, movement, and rotation are clearly present in the work and at the heart of the artistic concerns that Delaunay explored throughout her life.

The six colors chosen by the artist resonate with one another, modify each other, and complement each other—blue, for example, balances red. Chromatic forces  are created, animate the forms, and produce  a dynamic optical effect. Rhythm then arises from the repetition of forms and hues.

The frequent use of the title "Color Rythm" deserves to be highlighted: Sonia Delaunay adopts it as a leitmotif, a kind of mantra that reflects her renewed faith in the theory she long defended and consistently put into practice.

Finally, it should be added that 1973 was an important year in the artist's career, as Sonia Delaunay received the Grand Prix des Arts from the City of Paris that same year