I have the Ultimate 3-in-1 Color Tool...it tells me what colors best coordinate with a certain color that I'm using. For navy/white as your main color it tells me to use any of these as a split complementary, lighter blue, orange, yellow orange (mustard) or yellow. It also tells me that for a Triadic look to use blue, red, yellow green. Since your fabric is to clasic looking I would go with a gray blue or a mustard tone. Good luck with your choices.