Ralph Humphrey (1932-1990) was born in 1932 in Youngstown, Ohio, and attended Youngstown State University. He moved to New York in 1956, when Abstract Expressionism was in its heyday, and became a widely respected member of the generation of painters and sculptors that laid the groundwork for the American art of the 1960’s and 70’s. Influenced especially by the paintings of Mark Rothko, Mr. Humphrey specialized in subtly varied monochrome paintings whose strong luminosity was almost invariably countered, sometimes perversely, by thick stuccolike surfaces. A deep yet bright blue, full of intimations of red, became his signatory hue. Over the years, his monochrome fields of paint were divided or framed by bands of contrasting colors, and in the last two decades of his life the frames developed into windowlike motifs to which the artist occasionally added humorous touches: the intimation of a window shade or cloudy weather. Mr. Humphrey had his first one-man exhibition in New York City at the Tibor de Nagy Gallery in 1959 and over the years was represented by the Green Gallery, the Bykert Gallery, the Andre Emmerich Gallery, the Willard Gallery and the John Weber Gallery. His most recent New York City exhibition was in May at the Mary Boone Gallery. Mr. Humphrey taught painting for more than two decades in the graduate art department at Hunter College and was represented in the permanent collections of numerous public institutions, including the Museum of Modern Art and the Whitney Museum of American art.