gør farve usynlig på en form?

Jeg ønsker et program, hvor der er muligt at skinne formene, hvor der også er muligt at få farven lilla til at være usynlig. Jeg har en kode, som skulle kunne gøre det, men det virker ikke. Når jeg kører koden, bliver formen klippet rigtigt ud, og objekterne på formen er også rigtige, men selve formen har den farve, som det sidste skærmbillede, som på dette billede:

http://zcollection.sytes.net/pictures/ForkertForm.jpg

I et modul har jeg dette:

Public Declare Function SetWindowRgn Lib "user32" (ByVal hwnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
Public Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Public Declare Function ReleaseCapture Lib "user32" () As Long
Public Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Public Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hDC As Long) As Long
Public Declare Function SelectObject Lib "gdi32" (ByVal hDC As Long, ByVal hObject As Long) As Long
Public Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long
Public Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Public Declare Function CombineRgn Lib "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
Public Declare Function DeleteDC Lib "gdi32" (ByVal hDC As Long) As Long
Public Declare Function GetPixel Lib "gdi32" (ByVal hDC As Long, ByVal X As Long, ByVal Y As Long) As Long

Public Type BITMAP
    bmType As Long
    bmWidth As Long
    bmHeight As Long
    bmWidthBytes As Long
    bmPlanes As Integer
    bmBitsPixel As Integer
    bmBits As Long
End Type
'--------- CreateRectRgn ---------

'--------- CreateRectRgn ---------
Public Function GetBitmapRegion(cPicture As StdPicture, cTransparent As Long)
Dim hRgn As Long, tRgn As Long
Dim X As Integer, Y As Integer, X0 As Integer
Dim hDC As Long, BM As BITMAP

hDC = CreateCompatibleDC(0)
If hDC Then
    SelectObject hDC, cPicture

    GetObject cPicture, Len(BM), BM
    hRgn = CreateRectRgn(0, 0, BM.bmWidth, BM.bmHeight)
    For Y = 0 To BM.bmHeight
    For X = 0 To BM.bmWidth
    While X <= BM.bmWidth And GetPixel(hDC, X, Y) <> cTransparent
    X = X + 1
    Wend
    X0 = X
    While X <= BM.bmWidth And GetPixel(hDC, X, Y) = cTransparent
    X = X + 1
    Wend
    If X0 < X Then
    tRgn = CreateRectRgn(X0, Y, X, Y + 1)
    CombineRgn hRgn, hRgn, tRgn, 4
    DeleteObject tRgn
    End If
    Next X
    Next Y
    GetBitmapRegion = hRgn
    DeleteObject SelectObject(hDC, cPicture)
End If
DeleteDC hDC
End Function



Hvor i formen har jeg dette:

If hRgn Then DeleteObject hRgn
hRgn = GetBitmapRegion(Me.Picture, &HFFFFFF)
SetWindowRgn Me.hwnd, hRgn, True