Blue is warmer than red?

Red colors are arousing, blue colors calming, so at first the results of Ho et al. seem counter-intuitive. A red object at the same temperature as a blue object feels colder, and they suggest that this is because our prior expectation from the red color that it should be warmer biases our perception to make it seem cooler than it is.

It is commonly believed that reddish color induces warm feelings while bluish color induces cold feelings. We, however, demonstrate an opposite effect when the temperature information is acquired by direct touch. Experiment 1 found that a red object, relative to a blue object, raises the lowest temperature required for an object to feel warm, indicating that a blue object is more likely to be judged as warm than a red object of the same physical temperature. Experiment 2 showed that hand colour also affects temperature judgment, with the direction of the effect opposite to object colours. This study provides the first demonstration that colour can modulate temperature judgments when the temperature information is acquired by direct touch. The effects apparently oppose the common conception of red-hot/blue-cold association. We interpret this phenomenon in terms of “Anti-Bayesian” integration, which suggests that the brain integrates direct temperature input with prior expectations about temperature relationship between object and hand in a way that emphasizes the contrast between the two.