I was wondering, if there is indeed a colour difference between these two colours. Often, I see resellers / vintage shops using both of them in their descriptions, sometimes interchangeable it seems. To my eye chestnut seems to be a lighter, less reddish brown than cognac but it could also be differences in different production patches. At the moment, there seems only cognac to be in Production, as far as I know.
Happy to get any insights ☺️!
Happy to get any insights ☺️!