This Chinese character 润, whose Pinyin version is rùn, has multiple meanings in Mandarin. As you mentioned, 润 could mean embellish. So, 润色, which literally means embellishing colors, actually refers to polishing a piece of writing.
Apart from this meaning, 润 could mean moisten. So, 雨润万物 could mean that rains moisten a myriad of things. 润 could also mean profit or remuneration. So, 润笔 could mean remuneration for literary or artistic works. 润 could be used as an adjective to mean smooth, for instance, 莹润 could mean bright and smooth.
Of course, nowadays when people hear this Chinese character, they could also associate this with another meaning, i.e., emigrate to other countries. This new usage was first circulated online in small circles and later has become a well-known slang among more Chinese netizens. Perhaps you would ask: why does 润 have anything to do with this new meaning?
Well, 润 could be written as run in alphabet letters. And it happens to share the same spelling with an English word run. As a result, 润出去 refers to emigrating to other countries. And China has already witnessed this and huge outflow of assets in recent years, when richer people, who have means and opportunities, apply for and get new identities in other more advanced countries, for instance, America, Canada and Australia.