' If a color style attribute is to be rendered,
' compare its value to purple. If it is not set to
' purple, add the style attribute and set the value
' to purple, then return false.
Protected Overrides Function OnStyleAttributeRender(name As String, _
    value As String, _
    key As HtmlTextWriterStyle) _
As Boolean

    If key = HtmlTextWriterStyle.Color Then
        If [String].Compare(value, "purple") <> 0 Then
            AddStyleAttribute("color", "purple")
            Return False
        End If
    End If

    ' If the style attribute is not a color attribute,
    ' use the base functionality of the
    ' OnStyleAttributeRender method.
    Return MyBase.OnStyleAttributeRender(name, value, key)
End Function 'OnStyleAttributeRender