Being confronted with dirt poses a potential risk of contamination and evokes a feeling of disgust. People with a high disgust propensity can barely tolerate even the slightest deviation from cleanliness. This is why disgust propensity leads to a favouring of the brightest colours in the light spectrum and the detection of even slight differences in brightness. Hemophobics show physiological reactions such as aversion, nausea and syncope when confronted with fear-evoking stimuli. Although these reactions are atypical for anxiety disorders, they are typical responses to the confrontation with disgust stimuli. In this case the disgust reaction serves as a protection of the individual from contact with blood-relevant stimuli as potential carriers of diseases. The aim of this study was to examine people with either high or low scores on disgust propensity and hemophobia with regard to the performance of differentiation of colour contrasts of the colours red and grey. For this purpose, 101 women aged between 18 and 31 were split into extreme groups of the characteristics disgust propensity, disgust sensitivity and blood phobia. Using a computer-assisted paradigm consisting of 72 tasks, the test persons performance of differentiation was determined. The test persons were shown two squares at the same time, both either red or grey, and they had to determine in what way the right square was different to the left square, either brighter, equally bright or darker. Besides that, two contrast graduations of “high”and “low” were defined. For all test persons a better performance of differentiation of the colour red and for high contrasts could be determined. These results are independent from the features disgust propensity and hemophobia. However, an influence of blood phobia on the performance of differentiation for high contrasts, especially for red tasks, could be determined.