I am trying to understand which syntactic role the word red has in this sentence:
We could colour the walls red.
My first thought was it being an adverb, but I have never heard someone saying colours could be used as adverbs. Also, the position is untypical for adverbs.
What part of speech is red in the sentence? What syntactic role does it play? Is it some sort of adjective-valency perhaps? Which other verbs (like to colour) have similar properties?