There are semantic constraints for the use of adverbs. hěn (很) is a degree adverb, which is semantically compatible only with degree-scalar attributes:
hěn (很)+scalar adjectives → 很漂亮 (very pretty)
hěn (很)+evaluative verbs → 很喜歡 (like it very much)
Therefore, *很紅色 is ungrammatical. But we can say 他很紅 "He (an actor or singer) is quite popular."