I was just reading this article about the discontinuation of Google's blob emoji for Android O and it seems to be generating some backlash, since a lot of people do like them (me included), particularly the version that came with Android 4.4.
The article makes a great case of why Android 4.4's emoji are iconic and look great. If Google seems determined to discontinue them, I think it would greatly benefit UBports to adopt them.
I know that my proposal sounds naive, but still this could be a point of differentiation for the project.
After a quick look at the Noto Emoji project , this set of emoji was gradually replaced, culminating on this commit.
The black and while font NotoEmoji-Regular.ttf is from Dec 15, 2015 and still in this style.
It is perfectly possible, for example, to fork EmojiOne Color SVG-in-OpenType font project and substitute the SVGs appropriately with the Noto Emoji Blobs.