Colour line and Ideological barrier

Colour line noun - Barrier preventing blacks from participating in various activities with whites.

Ideological barrier and colour line are semantically related. In some cases you can use "Ideological barrier" instead a noun phrase "Colour line".

Ideological barrier noun - A barrier to cooperation or interaction resulting from conflicting ideologies.

Colour line and ideological barrier are semantically related. Sometimes you can replace phrase "Colour line" with "Ideological barrier", this phrases are similar.