To compare in order to show unlikeness.
To stand in opposition; show unlikeness.
Partial unlikeness between things compared; also, the things thus opposed.
When two words are set in contrast, or in opposition to each other, they are both emphatic. – The Grammar of English Grammars by Goold Brown
Fill 2 needles with 2 colors which contrast well. – The Ladies' Knitting and Netting Book by Miss Watts