I became a Community Moderator in October of 2018. I was probably in the right place at the right time, and apparently I said the right things to the right person.
It's a little funny, when that happened Imgflip's featured streams like m/politics and m/repost were also created, and every Moderator on Imgflip had the green tag. Every existing stream owner, and the Global Moderators too.
About a thousand users at the time that were existing stream owners would have seen the green MOD tag next to their username if they commented inside their stream, or looked at their existing comments inside their stream.
The different colors for Stream and Global Moderators were added around January 2019. As far as I know, I'm the only green MOD left.
Work is a four letter word. Just like Moderators on Reddit, I'm a volunteer.