MaxGUI - Changing Gadget Color and Alpha?

I can change the textarea colours no problem, the main window doesn't seem to get affected by SetGadgetColor and if you try it on a menu, it causes an unhandled exception.

Strict

'CONSTS
Const MENU_NEW=101
Const MENU_OPEN=102
Const MENU_SAVE=103
Const MENU_CLOSE=104
Const MENU_EXIT=105

Const MENU_CUT=106
Const MENU_COPY=107
Const MENU_PASTE=108

Const MENU_ABOUT=109

'SETUP
Global mainWindow:TGadget = CreateWindow("Edit Pad",30,20,500,400,Null, WINDOW_TITLEBAR|WINDOW_RESIZABLE|WINDOW_MENU|WINDOW_STATUS|WINDOW_ACCEPTFILES)
Global filemenu:TGadget=CreateMenu("&File",0,WindowMenu(mainWindow))

	CreateMenu"&New",MENU_NEW,filemenu,KEY_N,MODIFIER_COMMAND
	CreateMenu"&Open",MENU_OPEN,filemenu,KEY_O,MODIFIER_COMMAND
	CreateMenu"&Close",MENU_CLOSE,filemenu,KEY_W,MODIFIER_COMMAND
	CreateMenu"",0,filemenu
	CreateMenu"&Save",MENU_SAVE,filemenu,KEY_S,MODIFIER_COMMAND
	CreateMenu"",0,filemenu
	CreateMenu"E&xit",MENU_EXIT,filemenu,KEY_F4,MODIFIER_COMMAND

Global editmenu:TGadget=CreateMenu("&Edit",0,WindowMenu(mainWindow))
	CreateMenu "Cu&t",MENU_CUT,editmenu,KEY_X,MODIFIER_COMMAND
	CreateMenu "&Copy",MENU_COPY,editmenu,KEY_C,MODIFIER_COMMAND
	CreateMenu "&Paste",MENU_PASTE,editmenu,KEY_V,MODIFIER_COMMAND

Global helpmenu:TGadget=CreateMenu("&Help",0,WindowMenu(mainWindow))
	CreateMenu "&About",MENU_ABOUT,helpmenu

Global font_Courier:TGUIFont = LoadGuiFont("Courier New", 12)

Global textArea : TGadget = CreateTextArea(0, 0, ClientWidth(mainWindow),ClientHeight(mainWindow), mainWindow)
	SetGadgetFont(textArea, font_Courier)
	SetGadgetColor(textArea,155,0,0)
	SetGadgetColor(textArea,255,255,255,False)


'setting menu colour causes an exception
'SetGadgetColor(fileMenu, 155,0,0)
'SetGadgetColor(fileMenu, 255,255,255, False)

UpdateWindowMenu mainWindow





'MAIN
MainLoop()


Function MainLoop()

While True
	WaitEvent 
	Select EventID()
		Case EVENT_WINDOWCLOSE
			End
		Case EVENT_MENUACTION
			Select EventData()
				Case MENU_EXIT
					If Proceed("Are you sure you want to quit?") = 1 Then End
				Case MENU_SAVE
					SaveFile()
				Case MENU_ABOUT
					Notify "Simple notepad type thing in BMax~n (C) me"
			End Select
			
		Case EVENT_APPTERMINATE
			If Proceed("Are you sure you want to quit?")=1 Then End
			
		Case EVENT_GADGETACTION
			?debug
				'Print "EVENT_GADGETACTION"
			?
Rem
			Select EventSource()

					
			End Select
EndRem

		Case EVENT_WINDOWSIZE
			HandleResize()
			
		Case EVENT_WINDOWACCEPT
		
	End Select

Wend

End Function


Function HandleResize()
	SetGadgetShape(textarea, 0,0, ClientWidth(mainWindow),ClientHeight(mainWindow))
Rem
	textarea.Width = ClientWidth(mainWindow)
	textarea.Height = ClientHeight(mainWindow)
EndRem
End Function


Function SaveFile()
	Local FileName:String
	FileName = RequestFile("Save File...", "Text File:txt", True)
End Function