In an advance publication reference (BPatG 183 11.06) of 27 August 2008, the German Federal Patent Court ("Bundespatentgericht") published the following guidlines on abstract colour trade marks; sections 8 (2) No. 1, (3) German Trade Marks Act. (Unofficial translation)
Colour trade mark Signal Yellow ("Farbmarke Signalgelb")
1. Extraordinary circumstances in the sense of the decision of the ECJ on the distinctiveness of abstract colour trade marks (see EuGH GRUR 2003, 604 - Libertel) can only be assumed in cases, where the claimed goods or services are a part of an enclosed, specific segment of the market, which is independent from the trade mark habits of other business sectors.
2. This is not the cases for free of charge e-mail services. The function of designating trade origin of a colour trade mark can consequently not be determined with reference to the concrete service.
3. As such, the distinctiveness cannot be examined. A trade mark registration is only possible through acquired distinctiveness ("Verkehrsdurchsetzung").
Case reference 29 W (pat) 58/06 of 7 May 2008.