One way to hold this word: a colour that is wrong, and that you cannot look away from. Think of a sky glowing yellow at midnight — the light is too much, the wrong shade, and it makes everything under it look strange. From that one picture, lurid moves outward twice. It lands on colours that are simply too bright for comfort, and it lands on stories told in colours that are too strong: the shocking parts turned up until the reader stares.
Wiktionary records it as borrowed from Latin luridus, meaning pale yellow or wan. That sickly colour is still visible in the literary light sense, and it is the colour the other two senses grew out of.
Wiktionary 記它借自拉丁文 lūridus，意思是「蒼黃的、沒有血色的」。那個病色在文學用法的「慘黃幽光」裡還看得見，另外兩個意思也是從這個顏色往外長出來的。
Wiktionary entry for lurid, etymology_text supplied in packet (kaikki:3f6f69a190036ae4:921900771:14266)
Three branches
不自然的光
離拉丁文老意思最近的一支，核心畫面本身。
adjective · C1
Used about light, fire, smoke or sky: shining with a strange sickly glow, often yellow or dull red, which makes everything under it look pale and frightening. Mostly found in older and literary writing.
慘黃幽光的
亮到刺眼的顏色
把「不自然的顏色」從幽光挪到日常物品上，剩下的就是「太亮、有點俗」。
adjective · C1
So bright in colour that it looks harsh, and stands out much more than the speaker would like.
俗豔刺眼的
講得太刺激的描述
把「顏色開太亮」的畫面借去講文字：細節被調到最刺眼的那一格。
adjective · C1
Used about a story, report, headline or description that is shocking on purpose, dwelling on sex, violence, crime or scandal in order to catch attention.
聳動露骨的