Norwegian courts rule that purple is not perceived as a trade mark for inhalers. 

This case has gone through all instances in the Norwegian court system, with the Norwegian Supreme Court rendering its first decision on colour marks in December 2017. Overall, the courts find that neither purple, nor specific shades of purple, have protection as unregistered trade marks for inhalers for GlaxoSmithKline in Norway.

See Kluwer Trademark Blog