Colour and font size in message popup

Hi,

Ive had some great help making a code to force a pop up window to appear when i certain vailue is reaced in a particular row.

the code is below

Just wondering if itis possible to change the background colour of the message box (to RED as it is a critical warning) and to enlarge the font size as well



THE CODE

Dim B As Integer
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
A = Application.WorksheetFunction.CountIf(Range("B:B"), "HELD - Cargo is held under Customs control")
If A = B Then
    Exit Sub
Else
   B = A
   MsgBox String(10, vbLf) & String(50, " ") & "STOP DO NOT SELL" & String(50, " ") & String(10, vbLf)
End If
End Sub