motley has 30 distinct synonyms spread across 5 of its 7 senses. 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.
a collection containing a variety of sorts of things
“a great assortment of cars was on display”
a garment made of motley (especially a court jester's costume)
a multicolored woolen fabric woven of mixed threads in 14th to 17th century England
make motley; color with different colors
consisting of a haphazard assortment of different kinds
“an arrangement of assorted spring flowers”
having sections or patches colored differently and usually brightly
“a jester dressed in motley”
Synonyms, antonyms and the broader and narrower relations for motley come from Princeton University’s WordNet. Full sources and licences.