Cadbury has lost more ground in its long-running battle to protect the particular purple it uses to wrap its chocolate.
After losing an appeal last month, Cadbury has given up a trade mark.
Lawyers said the company may have decided the trade mark application is unenforceable after a court ruled it was too wide-ranging.
The move makes it harder for Cadbury to stop a rival from using a similar colour for its products, a lawyer said.
In 2012 Cadbury