this is the first time i have seen an emoji rendered here
♠♦ There's a whole bunch of them[1]! ♦♠
[0]: https://www.compart.com/en/unicode/U+2665 [1]: https://www.compart.com/en/unicode/block/U+2600
Emoji are full-color and can't have their color changed in a word processor in the same way.
Also, in practice those characters' appearances are tied to the font you've selected, while emoji's appearances are usually tied to the OS you're using (although sometimes the specific app -- e.g. Gmail in the browser on a Mac uses Android-style emoji rather than Mac-style emoji).
Though color fonts aren't restricted to emojis, they can be used for any characters, they just aren't very common.
When I said "standard characters" perhaps I should've been clearer. I meant "they're non-emoji characters". Sorry, I didn't realise it would cause confusion.
> For the majority of characters that are not emoji, the UTC looks for evidence of existing usage as text. Proposers need to establish that there is some reasonable body of text, either modern or historic, that uses that character.
...
> For emoji, rather than look for evidence of existing textual use — since emoji effectively cannot exist in text until they are encoded — we look for evidence of likely high usage once they are encoded, plus a number of other factors.