*ColorDevice: False
*DefaultColorSpace: Gray
*VariablePaperSize: True
*LandscapeOrientation: Plus90


updfate 2 lines as follows:


*ColorDevice: True
*DefaultColorSpace: CMYK


*CloseUI: *FXOutputMode
*OpenUI *FXColorMode/Output Color:PickOne
*OrderDependency: 20.0 AnySetup *FXColorMode
*DefaultFXColorMode: Color
*FXColorMode Color/Color: "
  1 dict dup /ProcessColorModel /DeviceCMYK put setpagedevice


Update 3 lines as follows:


*DefaultFXColorMode: Black
*FXColorMode Black/Black: "
  1 dict dup /ProcessColorModel /DeviceGray put setpagedevice


Some PPD Files the Black and White option may be called MONO, not GRAY as shown in the example


By making this adjustments users won't be able to print in color to the BW printer queue.
(two queue setup required)