How can I slowly fade all the Colors of a Window either to black or to
white?

Does anybody know?

Thanks in advance!!

Sure do, heres some code:

In General Declarations

' global variables for screen color settings
'  the integer values should be set with true or false to get valid values
' any or all back colors could be set at one time

Global RedBack As Integer                       '  set to decide if you
want to add red         use true or false
Global GreenBack As Integer                '  set to decide if you want to add green    
use true or false
Global BlueBack As Integer              ' set to decide if you want to add blue         use
true or false
Global blnHighColorMode As Boolean      ' setting to false will turn off faded
backgrounds
Global FadeBlending As Double           ' set as to how quickly you want the color
to fade to black

Declare Function GetDeviceCaps Lib "gdi32" (ByVal hdc As Long, ByVal nIndex
As Long) As Long
Declare Function GetDC Lib "User32" (ByVal hWnd As Long) As Long

Function GetMaxColors(frm As Form) As Long

    Dim myhdc As Double
    Dim NUMCOLORS As Double         '  Number of colors the device supports
    Dim SIZEPALETTE As Double       '  Number of entries in physical
palette
    Dim COLORRES As Double          '  Actual color resolution

    NUMCOLORS = 24
    SIZEPALETTE = 104
    COLORRES = 108
    myhdc = GetDC(frm.hWnd)
    GetMaxColors = GetDeviceCaps(myhdc, 24)

End Function

Sub FadeForm(frm As Form)
'  Draws a fading background on a form
'  Cannot be used to draw on a MDI Parent form
    Dim SaveScale%, SaveStyle%, SaveRedraw%
    Dim i&, j&, x&, Y&, pixels&

    If GetMaxColors(frm) > 0 Then
    Else
        If blnHighColorMode = True Then
            'Save current settings
            SaveScale = frm.ScaleMode
            SaveStyle = frm.DrawStyle
            SaveRedraw = frm.AutoRedraw

            ' Paint Screen
            frm.ScaleMode = 3
            pixels = (frm.Height * FadeBlending) / Screen.TwipsPerPixelY
            x = pixels / 64# + 0.5
            frm.DrawStyle = 5
            frm.AutoRedraw = True
            For j = 0 To pixels Step x
                Y = 240 - 245 * j \ pixels       ' can tweak this to
preference actually causes color banding
                If Y < 0 Then Y = 0              'just in case
                frm.Line (-2, j - 2)-(Screen.Width + 2, j + x + 3),
RGB(-RedBack * Y, -GreenBack * Y, -BlueBack * Y), BF
            Next j

            ' reset to previous settings
            frm.ScaleMode = SaveScale
            frm.DrawStyle = SaveStyle
            frm.AutoRedraw = SaveRedraw
        End If
    End If
End Sub