You can take a look at this site that the steps are way more simple. This one might give you the answer you are looking for:
http://www.askstudent.com/techtips/categorize-emails-and-identify-sender-using-different-colors-in-outlook/
Also, you can add a small function to your Outlook VBA project that displays the
dialog. You might call it with alt+f8, or customize the toolbar.
http://www.vboffice.net/sample.html?mnu=2&pub=6&lang=en&smp=69&cmd=showitem
Description
Since Outlook 2007 you can't directly display the categorizer for outgoing e-mails.
This small example demonstrates how to display the dialog for the active e-mail.
Public Sub ShowCategoriesDialog()
Dim Mail As Object
Set Mail = Application.ActiveInspector.CurrentItem
Mail.ShowCategoriesDialog
End Sub