I know Princess uses different colors in the carpet on both sides (As I recall, it's the accent color in the carpet, not the entire coloring for it). I honestly don't remember whether it was red and green or not. I'm generally paying attention to the odd/even numbers to figure out which side I'm on instead.

And of course, something to keep in mind, if they used left and right, they'd really need to specify "left of the ship". Your left might be the right side of the ship depending on which direction you're facing, but the port side is always the same side.