Sentence:  Linking moods with colours is one example of <WSD>synaesthesia</WSD>. ... As a tool for improving writing, the idea of <WSD>synaesthesia</WSD> is versatile and innovative. Why use only visual references to describe visual impressions? Why just describe sounds using sound-related words? Play with cross-matching the senses. 
Meaning of the word marked with <WSD> tags:  A literary or artistic device whereby one kind of sensation is described in the terms of another.