Section 29. Painting of courts and shafts

The exterior surface of all walls
  of  all  courts and shafts of multiple dwellings, except of outer courts
  opening on a street, and courts having  dimensions  of  at  least  fifty
  percent  in excess of the minimum set forth in section twenty-six, shall
  be of a lightcolored brick or stone, or  be  thoroughly  whitewashed  or
  painted  a light color by the owner and be so maintained. Such whitewash
  or paint shall be renewed whenever necessary, as may be  determined  and
  required by the department.