Feeling blue may not be all bad when it comes to enjoying a good night's sleep.
Those with bedrooms this colour tend to get the best rest - nearly eight hours a night - and wake feeling happy and positive.
According to a survey, it is linked to calm, soothing feelings and is thought to slow the heart rate and even reduce blood pressure.
Green and yellow are also winners, with those choosing these colours clocking up roughly seven hours and 40 minutes of sleep.
However, it's best to avoid purple, which is too stimulating and can cut nightly hours of rest to under six. Grey and brown get the thumbs-down for being too dreary and depressing.
Chris Idzikowski, from the Edinburgh Sleep Centre, said "there are specialised receptors in the retina of our eyes, which are most sensitive to the colour blue.
"These feed information into an area deep in our brain that controls 24-hour rhythms and affects how we feel."
Suzy Chiazzari, a holistic interior design consultant, said blue makes our brain think of calm waters and the sky, which we find very soothing.
"Certain shades of yellow and green are relaxing too, known to reduce stress," she said.
"'Purple is reported to stimulate creativity and the unconscious mind. Sleeping in a purple room is more likely to promote vivid dreams or even nightmares."
The survey of 2000 Britons by hotel chain Travelodge also revealed an effect on love lives.
Despite red being seen as the colour of passion, couples with this hue in their bedrooms made love once a week compared to three times for those with walls in a caramel shade.
- DAILY MAIL