五花八门
Meaning
A bewildering variety of kinds or methods — often mildly critical of how many there are.
In a sentence
The app store offers 五花八门 ways to learn a language.
Usage note
Unlike 五光十色 it can carry a hint of "too many to choose from".
Where you see it in Brain Challenge
This idiom appears in the picture-idiom levels as a picture or number clue. When the clue shows numbers, the digits usually become the first characters of each half of the idiom — that is why so many chengyu start with 一, 三, 五, 七, 九 or 十.