dark bread vs whole meal bread

dark bread and whole meal bread both are nouns.

Word	Noun	Adjective	Verb	Adverb
dark bread	Yes	No	No	No
whole meal bread	Yes	No	No	No

As nouns, dark bread and whole meal bread are synonyms defined as:

Other synonyms of dark bread include brown bread, whole wheat bread.

dark bread (noun)	whole meal bread (noun)
bread made with whole wheat flour	bread made with whole wheat flour