IPA: /kəmˈplɛmənˌtæl/
KK: /kəmˈplɛməntəl/
Related to something that completes or enhances another thing.
The two colors are complemental, making the design more vibrant.
Complemental → It is formed from "com-" (meaning together) and "plere" (meaning to fill). The word "complemental" refers to something that completes or fills out something else, working together to enhance or complete a whole.
Think of things that work 'together' ('com-') to 'fill' ('plere') in gaps or enhance each other — that's what complemental means.