The ensign of Denmark is some of the oldest country wide flags nonetheless in use today; proposing a white move on a purple

https://numberfields.asu.edu/NumberFields/show_user.php?userid=6642182

The ensign of Denmark is one of the oldest nationwide flags nonetheless in use at present; proposing a white go on a red background often called Dannebrog dates to come back as a minimum to the thirteenth century as an emblematic illustration.