What a cool quilt! I'd do a double border -- dark tone for inner border (wedgewood blue or deep red) and then something light and bright for a larger outer border (yellow, orange or pink depending on the inner's color). Then, bind in something darker again so it doesn't show dirt ... probably the same color as inner border.
I'd probably do a 2" finished inner border in the deep red followed by a 3" or 5" finished outer border in orange, then bind in red. They both read as solid colors & it would bring out that beautiful orange in the quilt that is already quite striking and using analogous colors will help give the entire quilt a nice, rich theme.
If you want to go with blue, I'd maybe do the darker blue for the inner border & a lighter blue in the outer border.