color barrier vs roadblock

color barrier and roadblock both are nouns.

Word	Noun	Adjective	Verb	Adverb
color barrier	Yes	No	No	No
roadblock	Yes	No	No	No

As nouns, roadblock is a hypernym of color barrier; that is, roadblock is a word with a broader meaning than color barrier:

color barrier: the barrier preventing Blacks from participating in various activities with whites
roadblock: any condition that makes it difficult to make progress or to achieve an objective

Other hypernyms of color barrier include barrier.

color barrier (noun)	roadblock (noun)
the barrier preventing Blacks from participating in various activities with whites	a barrier set up by police to stop traffic on a street or road in order to catch a fugitive or inspect traffic etc.
	any condition that makes it difficult to make progress or to achieve an objective