Cool is related to Fall. Fall is a synonym of Light. 
Simple is related to Ordinary. Ordinary is a synonym of Plain. Plain is related to Obvious. Obvious is a synonym of Evident. 
Cool <--RelatedTo--> Fall <--Synonym--> Light 
Simple <--RelatedTo--> Ordinary <--Synonym--> Plain <--RelatedTo--> Obvious <--Synonym--> Evident 