Judgment of the Court of 6 May 2003 in Case C-104/01 (Reference for a preliminary ruling from the Hoge Raad der Nederlanden): Libertel Groep BV v Benelux-Merkenbureau, (Trade marks — Approximation of laws — Directive 89/104/EEC — Signs capable of constituting a trade mark— Distinctive character — Colour per se — Orange)