On 1 January 2020 Slovenia implemented plain packaging legislation for tobacco products. New packets must be non-branded, must include graphic warnings about the health effects of smoking and must be made using Pantone 448 C, an unattractive dark-brown colour.

Source: https://www.total-slovenia-news.com/business/5279-ugliest-colour-in-the-world-comes-to-slovenia-s-uniform-cigarette-packaging