When Americans describe the flag of the United States, the colors are identified as "Red white and blue". Why are the three colors invariably listed in that order?
I wrote a post some months back on early uses of this phrase (incongruous though that may be, given my research speciality).
The upshot appears to be: because it rhymes with "Tippecanoe".
Its earliest appearance is in a song for Harrison's electoral campaigns in 1836 and 1840, commemorating him as "the hero of Tippecanoe". In a way that's not a complete answer: the phrase has a good ring to it in any case, independent of any song. And it was another song, "O Columbia, the Gem of the Ocean", that made the phrase really popular. But it's part of the answer, at least.
Just to add, the Norwegian flag colors are also always named in that order. "Norge i rødt, hvitt og blått" translates to "Norway in red, white and blue".