A simple class that create all a range of colors on an numeric item

CLASS
  STYLE
    COLORRANGE 255 255 255 100 0 0 # bianco a rosso scuro
    DATARANGE 100.0 30000.0
    RANGEITEM "res_mf"
  END
  STYLE
    OUTLINECOLOR 45 45 110
  END
END

An example here pmapper.beopen.it