Interesting from a graphic perspective, but light from a linguistics perspective. Not only do Russians and Koreans have more differentiation of blue, but they have different meanings: Blue is a feminine color in Korean semantics while Russian semantics link blue with adventure. A Korean blue heart emoji, then, has different uses than a Russian blue heart emoji, both of which are different from an American blue heart emoji (sadness, serenity).

None of this is universal, however, and semantic meanings shift. Red was traditionally a color of luck in Han Chinese culture but exposure to the west has increased the acceptance of "love". The lack of universal meaning of ideograms combined with the lack of universal meaning of colors tends to cause the creation of compound rebuses whose decoding relies on a shared cultural background.

The manufacturers leverage this: Android emoji used to be quite different by default from iOS emoji to the point where the rebus was broken. This enforced in-group brand affinity and led to insular fandom, always a win for manufacturers (if your text bubble is green you're obviously scum). Emoji, then, aren't truly universal and aren't designed to be; they're insular vernaculars designed to facilitate low-register communication among cliques. In general, the more familiar you are with someone the more emoji you use to communicate with them thus the more emoji you use, the more familiarity you engender. Manufacturers, then, benefit from a lack of universality because if they can get your friend to switch to an iPhone just so she can make out your puzzles, that's a sale they wouldn't have gotten otherwise.

It's basically gang tag semantics by Fortune 100 companies.