顏色本身就暗
最字面的一支：光暗下來之後，顏色變深，這裡就停在這一層，不往情緒走。
r · C1
In a way that looks dark in colour. It usually comes in front of another describing word, or after a verb such as painted, stained, or showed.
顏色深地；看起來暗地
核心畫面
One way to hold this word: the light in a scene has dropped. Start with what that does to the eyes — colours go deep, edges go soft, and you see the shape of a thing without being sure what it is. Then let the same drop in light move . A sentence you cannot pin down is dim in the same way a room is. A face with the light gone out of it is angry, sad, or about to say something you will not like. And a joke told in that low light still makes you laugh, only now you can see what it is laughing at. Every use of darkly is the same scene with the lamp turned down.
可以想成畫面裡的光被調暗了。先看它對眼睛做了什麼：顏色變深、輪廓變軟，你看得到東西的形狀，卻說不準那是什麼。接著把同…更多收起
可以想成畫面裡的光被調暗了。先看它對眼睛做了什麼：顏色變深、輪廓變軟，你看得到東西的形狀，卻說不準那是什麼。接著把同樣的「光變暗」往裡面搬。一句話讀得懂字卻抓不住意思，那種模糊和房間變暗是同一回事。一張臉上的光暗下來，就是生氣、低落，或者接下來要講的話不會好聽。在這種微光裡講的笑話你還是笑得出來，只是這次你看得見它在笑什麼。darkly 的每一種用法，都是同一個場景把燈轉小。From the word’s history
Wiktionary records darkly as Middle English derkly, that is dark plus -ly, with a parallel Old English form deorclice. So the word never carried anything but dark; the range comes from what English chose to point that darkness at.
維基詞典把 darkly 記成中古英語 derkly，也就是 dark 加上 -ly，古英語還有平行的 deorclīċe。換句話說，這個字本身從頭到尾只有「暗」一個意思；它的用法之所以這麼廣，是因為英文把這份暗指向了不同的東西——顏色、視線、臉色、笑點。
Wiktionary entry for darkly (etymology 1), kaikki:3f6f69a190036ae4:824530323:32671 — "From Middle English derkly, derkely, derkliche, derkeliche; equivalent to dark + -ly. Compare Old English deorclīċe, a parallel formation."
Four branches
光不夠，所以看不清、弄不懂
光暗下來的下一步：不只是顏色變深，而是連辨認都變困難，這份困難再從眼睛搬到腦子。
r · C1
In a way that cannot be seen or understood clearly, because there is too little light or too little information. It is used about a shape you can only half make out, and about an idea that stays unclear.
看不清地；晦澀地
臉色和語氣裡的暗
把變暗的畫面搬到人身上：臉上的光一收，情緒就沉下來，話也不再講白。
r · B2
In a way that shows anger, sadness, or a warning that something bad may happen. It describes how a person looks, speaks, smiles, or hints when the feeling behind it is heavy or unfriendly.
陰沉地；不懷好意地
在暗處講的笑話（固定搭配）
同樣的低光，但這次有人在笑；這一支只出現在 funny／humorous／comic 前面。
r · B2
Funny in a way that makes jokes about things that are sad, frightening, or wrong. The laugh and the bad thing arrive together, and that mix is the whole point.
黑色幽默地（好笑又沉重）