I have literally no US Soccer gear that would be wearable tomorrow night. Will have a normal jacket but an American flag and painted face suffice?
Try to wear red, if at all possible. Other than that, show up however you'd like. I recommend bringing something rainproof, and something to breathe through if you're in the supporters section.
Or Blue!!! Or White!!! Flag and pained face are awesome. Obviously, avoid green. And no matter what you wear, make noise and have fun.
Wear your freaking soul. On your sleeve. And in your voice. BRING IT. Send those Culeros back to Mexico with no points. And WEAR RED DAMMIT.
I'm wearing red pants, red t-shirt, red long-sleeve shirt, red jacket, red scarf, shoes with red accents... and a tan hat. Couldn't find my red one. :/ Oh and a clear poncho - if you are coming in today bring rain gear (preferrably red) as it's raining buckets.