When Things Smell A Funny Color

I have often heard people in Britain say in jest something like:

"I don't like that, it smells a funny color."

From time to time our senses play tricks with our brains, and we 'hear' or 'smell' colors. 
Such switching of sensory modalities and perception is called synaesthesia.

Synaesthesia is a neurological condition that often involves a ‘blending of the senses’. It is thought to affect less than 1% of the population, and people experience it in a variety of ways.
Some people may ‘see’ sounds, in that hearing sounds triggers them to see particular colours at the same time, while others might experience colours while reading simple black text. Whatever the sensory connections an individual experiences, it is always the same - particular tones or words will stimulate precisely the same colours or tastes.

Source:  Science Blog - University of Oxford.

Original Paper: PLoS One.