Jorge Eduardo Eielson called “vocal structures” or “audio paintings” to his experiments in vocal poetry, which were all based on combinatorial analysis and permutations. Of these experiments carried out over a period of five years (1972-1977), only one has remained, and its author has presented it on several public and private occasions, both in its recorded form as well as in live performances. This is the piece called Colores [Colors], which is based on the repetition of words that name colors: red, yellow, green, blue.