Polish idioms involving colour

I'd say that in simplest terms, idioms are phrasemes typical of a culture.

I'd say in simplest terms idioms are phrases that typically used do not convey literal meaning.

Phrasemes on the other hand are any commonly used phrases comprising 2+ words.

2+ could also mean a million.

2+ simply means plural. There's no upper limit for a phraseme, but I don't think there are any consisting of a million words.

Plural has no upper limit, does it?
And I never said a million words would be allowed in a phraseme or idiom, did I?

Oh, and why use + if 2 (without the +) is already plural?

I'm not sure if you're trolling me or you're simply unfamiliar with the convention. I'm assuming you're not so malicious, so let me rephrase that sentence:
"Phrasemes on the other hand are any commonly used phrases comprising at least two words. A single word cannot be classified as a phraseme"

"x+" where x may be any number is a convention to quickly type "at least x" or "x or more" (>= in mathematics).