Testify is a synonym of Prove. Prove is a synonym of Test. Test is related to Learning. 
Adult is a synonym of Blue. Blue is the opposite of Yellow. Yellow is related to Egg. 
Testify <--Synonym--> Prove <--Synonym--> Test <--RelatedTo--> Learning 
Adult <--Synonym--> Blue <--Antonym--> Yellow <--RelatedTo--> Egg 