話題偏離了分寸
把「顏色偏掉」放到說出口的話上面：題材跑到性上面，而且講得太白，聽的人就覺得越線了。
adjective · C1
Used about a joke, remark, story or comment that talks about sex in a rude way, so that it offends or embarrasses the people who hear it.
黃腔的、下流的
核心畫面
One way to hold this word: something has drifted away from the colour it is supposed to have. Put that picture on a person and you get a face that has lost its usual colour, so they must be feeling slightly ill. Put it on a joke and you get talk that has drifted out of the range people were willing to accept. In both cases nothing is broken; something has simply moved off the normal shade.
off-colour 可以想成「顏色偏掉了」。東西本來該是某個顏色，現在跑掉了一點，看起來就是不對勁。把這個畫面放在…更多收起
off-colour 可以想成「顏色偏掉了」。東西本來該是某個顏色，現在跑掉了一點，看起來就是不對勁。把這個畫面放在人身上，就是臉色不好、人不太舒服；放在笑話上，就是內容偏出了大家能接受的範圍。兩個意思都不是「壞掉」，而是「離開了該有的樣子」。這只是一個幫助記憶的想法，不是這個字的歷史。Two branches
氣色偏離了平常
把同一個畫面放回身體上：人不舒服的時候臉色會掉下來，旁邊的人第一眼看到的就是這個「顏色不對」。
adjective · C1
Feeling slightly ill — not really sick, but tired, weak or not quite right. This use comes after a verb such as feel, look or seem, never before a noun, and the source marks it as British English.
身體不太舒服的