I'd find a fabric from the line(s) of fabric used for the strips that picks up most/all of the colors. That's what I've done for mine.
On a related thread, I saw a jelly roll quilt that had a bit more prep wprk to it but turned out gorgeous. The strips were laid out onto a design board to distribute colors and patterns. Then each strip was cut into two pieces, where one piece was between 10" and 30". The strips in the top "row" were sewn end-to-end; the strips in the bottom row were sewn end-to-end, and then the end of Row 1 was sewn to the beginning of Row 2. The end result was a wonderful random distribution of color because of the varying lengths of strips. Gorgeous, gorgeous, gorgeous.