So I've recently been looking for an Apple M0116 for myself and would rather get the Alps SKCM Orange but the keyboard came with salmon as well. I've been told that there is no way to tell which it has besides pulling a keycap. I've noticed, though, that there is a trend where the higher serial numbers have Salmon and the lower serial numbers have Orange.
My plan is to collect some data and see if that always holds true or if there even really is a trend at all. We may be able to narrow down where the change happens as well. This would help when trying to buy on ebay since most sellers don't post pics of the switches. If this has already been tried, please let me know!