Toy can be used for Entertainment. Toy is related to Colorful. Colorful is the opposite of Gray. Gray is the opposite of Bright. 
Subject is related to Camera. Camera is related to Picture. Picture is related to Level. Level is related to Balanced. 
Entertainment <--UsedFor-- Toy <--RelatedTo--> Colorful <--Antonym--> Gray <--Antonym--> Bright 
Subject <--RelatedTo--> Camera <--RelatedTo--> Picture <--RelatedTo--> Level <--RelatedTo--> Balanced 