New York, Dec 5 (IANS): Shoppers tend to judge environmental friendliness of a brand on the basis of the colour it uses on the logo, says a study led by an Indian-origin researcher.

"What we are finding is that colour biases the way consumers make ethical judgements," said lead researcher Aparna Sundar, professor at the University of Oregon in the US.

The study found that shoppers consider retailers using blue or green in their logos to be more eco-friendly than retailers using red.

"Interestingly, blue is 'greener' than green in terms of conveying an impression of eco-friendliness, despite the frequent use of the word green to convey that idea," study co-author James Kellaris from the University of Cincinnati.

In one experiment, the researchers worked to pinpoint colours that were highly associated with environmentalism.

Shoppers were presented with a fictitious logo that was coloured using a colour associated with a known brand.

Armed with only an unfamiliar logo, the study found that shoppers consider retailers using Walmart's blue or Sam's Club's green in their logos to be more eco-friendly than retailers using Trader Joe's red.

Once researchers established a set of eco-friendly colours, they also identified colours perceived to be environmentally unfriendly.

The researchers then developed additional studies to test whether the colours impacted perceptions of the retailer's environmental friendliness.

Respondents were asked to share whether a fictitious retailer, DAVY Grocery Store, acted ethically in various morally ambiguous scenarios, such as when spraying water on produce.

Participants only saw the logo for DAVY, which was presented in either an eco-friendly colour or an unfriendly colour.

The results showed that exposure to a more eco-friendly colour in a retailer's logo influenced consumer judgments, and ethically ambiguous business practices seemed more ethical.

The study was published in the Journal of Business Ethics.