How about using the bright colors singly as on-point 4" or so squares, set in solid black; like a flim strip border but the squares on point. That would repeat the shape of the black diamond setting of the crosses, but add color.
Follow that with your light border as the drop, with another border of the zebra print, bound in black. A bright flange/piping between the white and zebra would make the drop really coordinate well. It could be a single color, such as the gold around the center block, or red, or a scrappy-style strip pieced from all the colors.