Final answer:
Robert and Sonia Delaunay introduced the artistic concept of simultanéité, a part of the Orphism movement, characterized by vibrant colors and a move away from traditional Cubism.
Step-by-step explanation:
Robert and Sonia Delaunay's Artistic Concept
Robert and Sonia Delaunay invented and employed the novel concept of simultanéité in art and design. Influenced by Michel Eugène Chevreuil's concepts and his law of simultaneously contrasting colors, they combined the overlapping planes and lines of Cubism with the concentration and vibrancy of color, resulting in the birth of Orphism. This movement embraced a more lyrical form of abstraction characterized by bright and pure colors. A friend described their version of Cubism as Orphism, which marked a distinctive shift from the previously dominant art styles and was considered a groundbreaking approach to visual arts.
Fernand Léger, mentioned in the array of artists, while related to Cubism, was known for his own unique style termed 'Tubism' and his work with primary colors. However, it was the Delaunays who are specifically associated with the term 'simultanéité.' This cooperation and innovation between Robert and Sonia Delaunay exemplifies their contribution to the modernist movements and their search for dynamism in art through color.