New York's 11 public hospitals are at the forefront of a national movement to standardize color coding of hospital wristbands to designate patient conditions. The goal is to prevent potentially dangerous mistakes, like giving the wrong food to an allergic child, but the nation's leading hospital-accreditation agency, the Joint Commission, has expressed caution about the new system, citing concerns about branding patients by their end-of-life choices, or inadvertently broadcasting those choices to family and friends who have not been consulted.