NEW YORK, N.Y. (AP).- The mural on the side of the building is no longer so vibrant. Its oranges, rust-reds and heavenly blues have dimmed and splotches of dead gray stucco show through where images have been rubbed out, as if someone took an enormous eraser to the wall. Finished in 1972 by renowned artist Arnold Belkin, the mural was created at a Manhattan playground in his trademark Mexican-influenced style but has been deteriorating slowly over the decades. There has been little impetus to preserve it until now. Residents are clamoring to have what may be the artist’s only outdoor U.S. work restored. At their request, Heritage Preservation, a Washington D.C.-based national organization devoted to preserving the country’s cultural artifacts, organized a team last week, to assess whether the 50- by 60-foot work, titled “Against Domestic Colonialism,” can be repaired. The prognosis for the mural was