All red: US market
Red/yellow: euro (ROW)
I read the DOT regs on tail-lights-- there's nothing that says you can't run the euro/ROW lights if you want to. The tail-lights can be red or yellow, as can the turn signals. The brake lights have to be red.
There's a guy who sells on ebay who has euro tail-lights with the dual filament (1157 bulb) sockets on either the red or the yellow side. If the dual filament socket is on the red side, I'd wire it so that the brake light was the brighter of the two and the tail-light was the dimmer. If it was on the yellow side, I'd make the tail-light the dimmer and the turn-signal the brighter.
Either way-- wire the brake light into the red lens.