Navy looks excellent with almost any color flower -- I suggest using a multicolor bouquet in bright colors.
I got married in June (15 years ago!) and had bridesmaids in navy carrying bouquets with red roses, fuschia (spelled right? I mean bright dark pink), yellow and orange lillies, and purple/blue iris. They were gorgeous, and the navy set them off perfectly!
My sister is getting married this October, and also has us in navy, and is doing multicolor bouquets -- just with more seasonal Fall colors, rather than my more Summer-y ones.
If you wanted the teal somehow tied in, you could have them tied with a teal ribbon...