Table Decor for Multiple Colors

My wedding colors are dusty blue and sage green. I having mismatched bridesmaids' dresses in these tones, and I have glassware, goblets, and tapers in these shades as well. Where I am stuck is what colors to do for the table runners! I am planning on having 8 ft banquets tables with white linens, with some of them pushed together to have longer tables (16 or 24 ft). I am not sure which combination of table runners to use or how to arrange them! I don't want either color to stick out as the "primary" color. Has anyone else done something like this? How did you decide what color runners to use and where?