I LOVE navy and pink: my 2 fav colors but for a beach wedding I have actually gone with navy, aqua, and coral. Its still (kinda) my fav colors with a twist that fits in with the beach setting. I say do blue and pink and just incorporate things found in the ocean or on the beach so that pink wont be a random color you choose esp if you choose hot pink. I believe having beach weddings are the simplest because you can use nature for lots of things! Good luck!