Think of a surface that has simply been left in the world. Air, rain, hands and daily use keep touching it, year after year, and they leave a thin layer behind: green on an old bronze bell, a soft shine on a table that has had forty years of dinners on it. One way to hold patina is as the layer time lays down on top of something. It sits on the surface, it takes years, and English usually likes it, because it is proof the thing is old and has been left alone. From there the word reaches in two directions: the colour of that green layer becomes a colour name, and the idea of a layer that is only on the surface becomes a way of talking about how something looks to other people.
From the word’s history
Borrowed from Italian patina, from Latin patina (a dish or pan), itself from Ancient Greek patane; a doublet of paten and possibly of pan.
從義大利文 patina 借入，再往上是拉丁文 patina（盤子、淺鍋），更早來自古希臘文 πατάνη。原本指的是器皿，後來才轉去指器皿表面因年久形成的那層東西，也就是今天的核心畫面。
Wiktionary entry supplied in packet (kaikki:3f6f69a190036ae4:621834545), etymology_text
登入就可以看每一支怎麼連回核心畫面。