hi all after a nigth spent i've found the solution

here the code

Private Sub change_font()
Dim pulsante As Shape
Dim sld As Slide
For Each sld In ActivePresentation.Slides
For Each pulsante In sld.Shapes
If pulsante.Name Like "CMD_*" Then
pulsante.OLEFormat.Object.ForeColor = &H400040
pulsante.OLEFormat.Object.BackColor = &HFFC0C0
End If
' pulsante.ForeColor = &H400040
Next pulsante
Next sld
End Sub