The Confederate battle flag, in many instances known by way of its unusual blue saltire against a crimson field

https://griffinxggr953.juniperbrief.com/posts/flags-of-honor-the-symbolism-behind-civil-war-colors-and-emblems-2

The Confederate combat flag, in general recognized by means of its designated blue saltire in opposition to a purple box, became a long lasting image of Southern satisfaction and background, regardless of its arguable connotations.