This was an interesting question - how do you pack if you want to carry on your bag, and you're on one of those airlines with a really LOW, and really STRICT, weight limit? (At least the destination was a warm weather vacation spot...)
My first advice was to get the lightest bag possible - nylon, with no structure at all. You should consider lining it with dry cleaning bags, or packing your clothes in plastic bags, because these bags are not waterproof. Beyond that, a very few items of clothing, in silk, linen or cotton. No jeans -they weight too much!
The other aspect of this request that really piqued my interested was the desire to wear navy, red and white - a color combination that can begin to look very "American Presidential Candidate" in a hurry! But avoiding anything that might look like a navy suit, and wearing nothing with stars on them (nor red and white stripes) seems to have worked well. Seersucker is lightweight and cool, sandals for sightseeing, and a sundress for sweltering days wrap up this tiny travel capsule.
tee shirt - Ralph Lauren, red earrings - inSync, watch - Brooks Brothers, scarf - Brooks Brothers, navy cardigan - Tory Burch, red linen pants - House of Fraser, moccasins - Gucci, cross-body bag - O.S.P.,
nylon bag - Liebeskind
striped scarf - Brooks Brothers, navy skirt - Chinti & Parker, white pleat-front tee, navy & white seersucker Capri pants - J.Crew, red sunglasses - Kate Spade, navy silk top - Joie, striped top - Raxevsky, chambray dress - Marc by Marc Jacobs, navy sandals - A.P.C., white sandals - Aerosoles