Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        Me.Label4.Text = "Nun muss sich der Text des labels auf Klik des" & _
        "Buttons verändern"
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        ' Hintergrundfarbe auf Blue setzen
        Me.Label4.BackColor = Color.Blue
        Me.Label4.Text = "Blauer Label"
    End Sub

Me.Label4.BackColor = System