Jim Crow vs colour line

Jim Crow and colour line both are nouns.

Word	Noun	Adjective	Verb	Adverb
Jim Crow	Yes	No	No	No
colour line	Yes	No	No	No

As nouns, Jim Crow and colour line are synonyms defined as:

Jim Crow and colour line: barrier preventing blacks from participating in various activities with whites

Other synonyms of Jim Crow include color bar, color line, colour bar.

Jim Crow (noun)	colour line (noun)
barrier preventing blacks from participating in various activities with whites	barrier preventing blacks from participating in various activities with whites