vba excel change backcolor of dynamically created scrollbar

I am stuck with trying to change the backcolor of a programatically created scrollbar. I can create the control but I get the error:

438 error of object not supporting the property or method

Here's the code:

Private Sub CommandButton1_Click()
    Set s = ScrollBars.Add(630, 220, 220, 38) '(left,top,width,height)
    s.BackColor = RGB(100, 100, 100) 'error happens here
End Sub