This is the 357th most frequent Croatian word.
onih
The Croatian word "onih" means "of those" or "of them" in English.
Here, 'onih' modifies 'dana' in its genitive plural form, evoking nostalgia for specific past days.
Sećam se onih dana provedenih na plaži.
I remember those days spent on the beach.
In this sentence, 'onih' is the genitive plural of the pronoun 'onaj', used to refer to specific items that are not near the speaker or listener, in this case, 'boja' (colors).
Trebamo izabrati jednu od onih boja.
We need to choose one of those colors.
'Onih' is used in genitive plural to describe 'grešaka', indicating a specific subset of mistakes under discussion.