A seven-year battle in Australia over purple cat food packaging has culminated in a truce between Mars Inc. and Nestlé. Under an agreement reached by the two pet food giants, Mars will have the “exclusive” right to use purple for its Whiskas brand cat food but will allow Nestlé’s Purina cat food to remain purple. Mars applied in 2002 to trademark the color for Whiskas in Australia, but Nestlé objected, saying it was already using purple for Purina. The registrar of trademarks originally agreed with Nestlé, but a federal court justice overturned that ruling, leading Nestlé to seek the agreement with Mars.