Domestic cats are often judged by color and stereotypes that go with the color, say U.S. researchers looking for a link between cat color and adoption rates. University of California, Berkeley, researchers surveyed 189 people with experience of cats as pets and found they were more likely to assign positive personality traits to orange cats and less favorable ones to white and tortoiseshell animals. And black cats have always had the misfortune to be associated with bad luck and witches. The study suggests feline typecasting can have a negative impact on adoption rates at animal shelters, a UC Berkeley release said. \"To date there is little evidence that these perceived differences between differently colored cats actually exist, but there are serious repercussions for cats if people believe that some cat colors are friendlier than others,\" psychology doctoral student Mikel Delgado said. \"Previous research supports the existence of \'black cat syndrome,\' where black and brown cats are less likely to be adopted than cats of other colors,\" Delgado said. \"We were interested in whether people\'s perceptions of the interaction between personality and coat color might play a part.\" Overall, orange cats and bi-colored cats were characterized as friendly, while black cats, white cats and tri-colored cats were regarded as more antisocial, the study found.