When we lived in Bishkek I learned the hard way that the bags of milk and kefir were easy to confuse since they're both blue (at least for 2.5% milk and kefir) and they'd usually be sitting right next to each other at Narodniy. I finally figured out that I had to check the bags at least three times to make sure I'd gotten milk instead of kefir (not that I dislike kefir, but I don't want to put it on my cracked wheat).
It's not just me that gets confused. My husband brought four bags of kefir home yesterday. He's an expert about checking the dates, but ended up with kefir. I've also gotten kefir accidently when I've bought it at a typical store here where someone else gets your food for you.
But even the milk and kefir producers get confused. The best time was when I opened a bag of what was labeled milk and kefir poured out. You never know what you're going to get.