"A true stimulant to the imagination, as the modernists saw it, color just might work social and spiritual transformations in a world cowering before the oppressive gray of industry, the foul brown of the trenches. It was 'a power which directly influences the soul,' in the words of Wassily Kandinsky, and at the Bauhaus, where he arrived in 1922 after leaving Communist Russia for Germany, he proposed the theory that primary colors are intrinsically linked with basic forms. In a kind of utopian holy trinity, triangles were yellow, squares red, and circles blue. These pairings became the foundation of a new design grammar to be applied not just to canvas and sculpture but to daily existence—refashioning everything from buildings and chairs to cradles and nursery toys. 'Fortunately,' Frank Lloyd Wright wrote, summing up the wishful credo of innocence reclaimed, 'human beings are really childlike in the best sense when directly appealed to by simple, strong forms and pure, bright color.'"
Sebastian Smee in a 2014 Atlantic article looks at books about color.