This is the 2691st most frequent Polish word.
czerwonych
The word "czerwonych" in English means "red" (genitive or accusative plural form) or "of the reds."
The word 'czerwonych' is an adjective describing the plural category of scarves (szalików), agreeing with the plural genitive case used here due to the usage of 'o' (denoting about).
To jest książka o historii czerwonych szalików.
This is a book about the history of red scarves.
Here 'czerwonych' is an adjective modifying the plural masculine personal form of 'ptaków' (birds), again in the genitive plural case.
Zobaczyłem stadko czerwonych ptaków nad jeziorem.
I saw a flock of red birds over the lake.
In this sentence, 'czerwonych' describes the plural neuter noun 'win' (wines) and aligns with the genitive plural case due to its inclusion in the possessive structure ('mam kolekcję').