In Italian “giallo” means yellow.
Giallo might be a lemon, the colour of a jumper and even a pair of trousers.
But what would you think if you heard the phrase mi piacciono i gialli? or guardo un giallo or leggo molto i gialli.
Because in Italian”giallo” is also a noun. We refer to a thriller book, movie or a detective story as un giallo. The origin of the use of this word in these contexts derives from the yellow covers of the very first thriller books published in Italy.