Colour purple rules the mailbox

As part of a wider survey, researchers Jan Charbonneau and Mike Brennan tested response rates to four questionnaire colours: red, green, blue and yellow. In a survey of 1600 New Zealanders, drawn at random from the Electoral Roll, the different coloured questionnaires generated significantly different response rates. They varied from 60 percent response to a non-purple questionnaire to 71 percent response to a purple one. Purple was also the most effective across gender and all age groups.

They say that clearly shows that questionnaire colour can affect mail survey response rates – a finding that may have wider application.

The result surprised Jan Charbonneau and Mike Brennan: “Purple seemed the least attractive and most likely to make the questionnaire hard to read.” They can only speculate on why purple shows as more effective. “Research on psychological effects suggests blue is cool, typifying restraint, yellow connotes warmth, and red and orange warmth and action. Not much is said about purple.”

One view is that it’s easier to see and find a purple questionnaire or reminder letter. “But this doesn’t explain our findings because all four colours were visually intrusive. It might be a combination of perceptual and emotional factors, given that purple has connotations with royalty and a market-leading brand of chocolate.”

The purple phenomenon is likely to interest to those who regularly conduct mail surveys: “ Many techniques are used to improve response rates,” say the Massey team, “but the most effective, such as pre-paid incentives and reminders, add to cost and effort. But other techniques that don’t cost more may also be effective. And one of these is colour.”

Source: Massey University