Cadbury has fought off Nestle over exclusive rights for the distinctive purple colour it has used on chocolate wrappers for more than 100 years. The Cadbury brothers are thought to have picked the colour as a tribute to Queen Victoria.
The group, which has been in a legal battle with its Swiss rival for three years, was granted a trademark for the tint - pantone 2865c - to be used on goods such as Dairy Milk, in 2008. Nestle challenged the ruling, saying the colour was not distinctive enough.
The UK Intellectual Property Office this week ruled in Cadbury's favour. One legal expert said that while it was an interim judgment, the decision was unlikely to be changed in the final report.
A spokesman for Cadbury said the group was pleased, adding that the colour was something those at the company "jealously guard".
In his ruling, Allan James, the registrar, said the colour purple had built a distinctive character associated with Cadbury. He rejected claims that Cadbury had registered the colour in bad faith as absurd.