Great design in that pattern.
I particularly like how the eye sees different secondary patterns, dependent on how one looks at it.
You have it nicely placed on a design wall.
Try auditioning your different possibilities, as to colour and widths.
My first thought was a pop of bright colour for the inner border and the backing.
Most any colour would be possible. Then a TOT black outer border and binding.
That is, unless you want a totally neutral colouring to the finished quilt.