An impossible puzzle.

Okay, this post really doesn't belong in this group, but I'm trying to figure out this puzzle and I figured this place is pretty well populated by smart people who might be able to get it.

Basically. This guy was wearing mismatched socks. I called him on it. He told me there was a reason to it, that the socks did match. That it was a puzzle.

Key points:
1. The red sock is on the left foot and the green is on the right. Both the color and the orientation are important.
2. It has to do with a vocation/industry, and this vocation is "often" a sport.
3. The capital of Papua New Guinea - Port Moresby - will give me a hint, because it's a homophone.

Please, either solve this for me, or tell me you're as baffled as I am.

Maybe something to do with port and starboard sides of a ship. At night, ships will hang a red lantern on the starboard side and a green lantern on the port side (I could have this backwards, I'm not a sailor), to indicate the ship's direction of travel to other ships. I can't solve the whole thing, and it certainly doesn't explain the "Moresby" part of "Port Moresby."

I'd guess it's something to do with shipping too. Port is definitely the left side of the ship and starboard the right. At night ships show a red light on the port side (left) and a green light on the starboard side (right). As to why ambushedbyasnail's guy was wearing socks of the appropriate colour on the appropriate feet - who knows? To remind him which was left and right? Something to do with ships passing in the night? Were the socks fluorescent?

Fishing is often, but not always, a sport, and is related to boats. But I',m unsure how that would relate to a reason for wearing red and green socks.

http://redandgreensocks.com/ ?

I suppose the socks "match", because they are each worn on the appropriate foot: red on the port side and green on the starboard. Strictly, though, this is not "matching" but forming a complementary pair, like a pair of socks marked "left" and "right". As for left and right: port wine is red, and if you are rowing, you face backwards, so the Red sock is on the Right.

Fishing might be a bit of a stretch. Sailing, however, is (or can be considered) a sport in its own right.

I've never heard MB's explanation with the wine and the backwards-rowing...but I agree with him/her and Thrin that boats or ships will display a red light on the port side (on your left if you're facing forward) and a green light to starboard. I believe this applies to aircraft as well as watercraft.
In areas where boats should keep to a specific channel (rivers, shallow or dangerous waters, harbour entrances, etc.) red and green buoys or lights will be displayed. In such cases, red will be to port when traveling toward open water (and to starboard when heading inland – hence the mnemonic Red Right Returning.)

I'm afraid I'm no help with the homophone of Port Moresby except for the Port - port connection, disregarding the second half entirely.

Good luck figuring it out!