My dad was appalled that I knew that the people who wore grey had lost and the people who wore blue had won the US Civil War, but didn't know which side had worn which color... the songs all had the boy in blue limping home and the boy in grey in the coffin, but never mentioned the geography.

There is the purple heather, too.

And the purple moor, looped by the ribbon of darkness. But that was a poem first...