The phrase "colour line" refers to the social, economic, and political barriers that prevent people of different races from fully interacting with one another. Synonyms for "colour line" include racial segregation, discrimination, bias, separation, and inequality. These words all describe the exclusion of individuals based on their race, ethnicity, or cultural background. Other synonyms for "colour line" include apartheid, bigotry, prejudice, and racism. Although these words describe negative attitudes and behaviors, they are important to use as a means of raising awareness and combating discrimination and prejudice. By acknowledging the existence of these issues, we can work toward building a more inclusive and equitable society.