w = 400
h = 400

#COLORKEY = #Green

If CreateImage(0, w, h)
  StartDrawing(ImageOutput(0))
  Box( 10,  10, 100,  70, #COLORKEY)
  Box(100,  10,  10,  40, #COLORKEY)
  Box(100, 200, 250, 180, #COLORKEY)
  For y = 200 To 380 Step 4
    For x = 100 To 350 Step 4
      Plot(x, y, #Blue)
    Next
  Next
  Box( 50,  50, 250, 200, #Blue)
  Circle(450, 150,  25, #COLORKEY)
  Circle(300, 150,  50, #COLORKEY)
  Circle(250, 250,  25, #Red)
  StopDrawing()
EndIf

If OpenWindow(0, 0, 0, w, h, "LWA_COLORKEY", #PB_Window_SystemMenu|#PB_Window_ScreenCentered)
 
  StickyWindow(0, #True)
 
  CreateGadgetList(WindowID(0))
  ImageGadget(0, 0, 0, w, h, ImageID(0))
 
  If OSVersion() >= #PB_OS_Windows_2000
    SetWindowLong_(WindowID(0), #GWL_EXSTYLE, GetWindowLong_(WindowID(0), #GWL_EXSTYLE) | #WS_EX_LAYERED)
    SetLayeredWindowAttributes_(WindowID(0), #COLORKEY, 200, #LWA_COLORKEY) ;|#LWA_ALPHA)
  EndIf
 
  Repeat
  Until WaitWindowEvent() = #PB_Event_CloseWindow
 
EndIf