You can look at it like this - the very early ones when the AK was young were OD green. As time progressed, lighter shades seemed to pop up and the golden colored ones were fairly common in the 1980's. They used both during their Afghan War. Later, they seemed to have gone back toward mostly OD green.
Whether it makes a difference or not to most people, beware of the airsoft copies out there. There are LOTS of the airsoft copy of the Russian AK sling floating around. There's also the new-made golden colored Russian slings that have the military style stamps, but their fake. It seems there are ingenious, capitalistic Russian vendors out there that know the collecting desire for such things and have found a great market online by selling the new-made/marked ones as "military." Those new-made ones have that definate "new" look to them.
If you want an original golden-colored one with the Afghan War era dates, check with AA-OK, Gunbroker, and eBay. You'll know its real by the style of stamp on it. It'll likely be the white recatngular "painted" style with a 1980's date.