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 trademark.
Lawyers said the company may have decided the trademark 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 won a case to stop other chocolate firms using the colour - known as Pantone 2865c.
Nestle challenged that, and in 2013 won an appeal.
The Court of Appeal said at the time the trademark application lacked "the required clarity, precision, self-containment, durability and objectivity to qualify for registration".