Honestly, I don't envy those that design and publish emojis, it's a cultural minefield. :-) has no color, gender, outfit or what-have-you. There's been a lot of debate about the skin tone of e.g. the thumbs up emoji (which now comes in half a dozen colors if the relatively ambiguous / non-human yellow isn't to your needs), the gender of emojis depicting jobs, and the color of outfits of emojis depicting jobs.
http://unicode.org/emoji/charts/full-emoji-list.html
I was doubtful of emojis at first, but now I'm loving the concept. They really help me communicate emotions that I wouldn't put into actual words. Smileys can't really do that.
Culturally I see it as a the first universal (limited) language, using standardized ideograms. Maybe in a few decades we can express full sentences and we will have a written language for all Humans to use. 21st century hieroglyphs.
https://en.wikipedia.org/wiki/Blissymbols http://www.radiolab.org/story/257194-man-became-bliss/
Take the thumbs up emoji - within my social circles, the exact same emoji can be interpreted both as a enthusiastic agreement ("Sure!") and also as a sarcastic affirmation ("Good for you.").
It's often difficult to infer the intended meaning, even with context, and in some circumstances I've found emojis have actually added significantly to the ambiguity and cognitive burden in parsing a text. That's not a problem I have often faced with simple smileys.