This is the 385th most frequent Danish word.
grønne
"Grønne" means "green" (plural or definite form) in English.
'Grønne' is an adjective describing 'æbler' (apples), again in plural form to match the noun.
De grønne æbler smager syrligt.
The green apples taste sour.
In this context, 'grønne' is used to describe the resulting condition of the wall after painting, an idiomatic usage in Danish.
Hun malede væggen grønne.
She painted the wall green.
Here, 'grønne' is an adjective describing the noun 'træer' (trees) and is in plural to agree with the noun.