This is the 9499th most frequent Polish word.
wielobarwnego
Multicolored.
The word 'wielobarwnego' is used as an adjective in its genitive singular form to describe 'lasu' (forest) as 'multicolored'.
Obraz przedstawiał widok wielobarwnego lasu jesienią.
The painting depicted the view of a multicolored forest in autumn.
In this sentence, 'wielobarwnego' is an adjective in its genitive singular form describing 'zachodu słońca' (sunset) to imply it is 'multicolored'.
Podziwiałem piękno wielobarwnego zachodu słońca.
I admired the beauty of the multicolored sunset.
Here, 'wielobarwnego' is an adjective in its genitive singular form modifying 'światła' (light), referring to its 'multicolored' nature.