First, Emoji characters on Android look different than on an iOS device. On Android, Emoji characters are black and white, but on iOS they look much better.
Some input methods support Emoji character input directly on Android devices. For this type of Facebook input method, if I find the Emoji character, then the character is still displayed as the one in Android. But on WeChat, the Emoji symbol looks the same as iOS.
So my question is: how to implement the same function as WeChat? See below two snapshots, the first is WeChat, then the second is Facebook.
Many thanks.
WeChat:

Facebook:

source share