According to a recent study eye colour plays a role in deciding how trustworthy others will think you are. Researchers simply asked a group of people to rate the trustworthiness of male and female faces. It was found that a majority of people found people with brown eyes to appear more trustworthy. This was true for both sexes but particularly so for men.
But it turns out that it is face shape that is more important and eye colour is a major factor because brown-eyed people tend to have certain facial characteristics. For the original story see here.