Le code ne marche pas, besoins d'aide

Private Sub Test()
    For Each i As Integer In RichTextBox1.Lines.Length

        Dim Text As String = RichTextBox1.Lines(i)
        RichTextBox1.Select(RichTextBox1.GetFirstCharIndexFromLine(i), Text.Length)
        RichTextBox1.SelectionColor = ColorForLine(Text)
    Next
End Sub

Private Function ColorForLine(Line As String) As color
    If Line.Contains("Processing", ) Then
        Return ColorForLine.Green
    End If
End Function