Apairantly not

After barely making it across the bridge, you hear two of the forest people arguing. It seems that just before they crossed the bridge, they each bought 10 pair of socks, and in fact, as far as color and size go, they each bought the same exact 10 pairs. Each person has 1 pair of green, 1 pair of blue, etc. etc... But now they have accidentally dropped all their socks and the socks are all mixed up in a pile on the ground.
Because it is pitch-black, they can't see what colors the socks are, but want to divide them up so that they each have the same colors that they bought, i.e. identical sets of green, blue, etc. Luckily the socks are all still in pairs, so they only have to pick up 20 pairs, not 40 individual socks.
The light used in crossing the bridge fell into a bottomless forest pit, so even though it is pitch-black, how can you help the two forest people get one pair each of every color, just like they had before they dropped them?
(Note: no lights, moon, cigarette lighter, etc...)