From the main menu in Emoji Keyboard Lite you can check out all the different themes. There are dozens, and they come in all stripes: from simple themes with flat colors to flashy ones with motifs from movies, TV shows, or video games.
Besides being able to download new themes, you can also get emoji packs to add to your keyboard. You can even download and apply new fonts to give the keyboard a properly unique look.
Emoji Keyboard Lite also offers autofill, autocorrect, and autocapitalization options. All the tools you could ask of a good keyboard, really. And on top of that, tons and tons of emojis.
Requires Android 4.1 or higher