auf die Schnelle habe ich nur eine englische Erklärung:
Etymology and definitions
The word "yellow" comes from the Old English geolu, or geolwe which derived from the Proto-Germanic word gelwaz. According to the Oxford English Dictionary, the oldest known use of this word in English is from The Epinal Glossary in the year 700.
In the English language, yellow has traditionally been associated with jaundice and cowardice. Yellow is associated with the word "caution" and is the second light on stop lights. The color is associated with aging as well, for both people and objects (e.g. "yellowed" paper). Ethnographically, the term "yellow" has been used as a slang term for both Asians ("yellow peril") and, in the early 20th century, light-skinned African-Americans (High yellow).
"Yellow" ("giallo"), in Italy, refers to crime stories, both fictional and real. This association began in about 1930, when the first series of crime novels published in Italy had yellow covers. The term "yellow movie" (黃色電影) can refer to films of pornographic nature in Chinese culture, and is analogous to the English "blue movie". Lastly, it is associated with sensational journalistic practices, or yellow journalism, and resistance to militant trade unions.
Ich hoffe, das hilft Dir trotzdem weiter
Wer eine Fremdsprache lernt, zieht den Hut vor einer anderen Nation.