Smells affect how we see colours, a study suggests

Different smells around us can change the way we process and experience colour, according to researchers.

Scientists from Liverpool John Moores University have carried out an experiment with 24 volunteers to test their theory.

We have five main senses - sight, smell, taste, hearing and touch - and past experiments have shown all five senses are closely interlinked and work together.

People tend to associate the smell of coffee with a brown or red colour

For this experiment volunteers were asked to sit in a room in front of a screen.

They were told not to wear any sort of perfume or deodorant.

Six different scents were then pumped into the room around them and they were asked to pick out specific colours.

In between each new scent the room was purified.

The smells used were caramel, cherry, coffee, lemon, and peppermint, and odourless water was used as a control.

Make sure there are no smells influencing your decision next time you choose what colour to paint your bedroom

When the volunteers were asked to select a "neutral grey" while breathing in the scent of coffee, they picked out a more reddish-brown colour.

But, when they inhaled a caramel scent, they chose a bluer version of grey, and the same happened with the lemon scent.

When the volunteers could smell peppermint they picked a warmer shade of grey, which surprised the researchers, because peppermint tends to be linked with cooler colours.

Likewise, they found cherry scents encouraged volunteers to choose a warmer shade of grey.

It was only when researchers pumped the scent of water into the room that volunteers chose a true grey colour.

The scientists said more research was needed before they could form any firm conclusions, but they were interested to find out how much our sight is influenced by smells, and whether this happens even for smells we are unfamiliar with.