primary colour for pigments has 1 distinct synonym spread across 1 of its 1 sense. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
any of three pigments from which all colors can be obtained by mixing
“the primary colors for pigments are red, blue, and yellow”
Synonyms, antonyms and the broader and narrower relations for primary colour for pigments come from Princeton University’s WordNet. Full sources and licences.