The design of a website is important for the success of a company. Colours play an important part in websites. The goal of this thesis is to find out how the use of colour in websites relates to the quality of websites. Different aspects are studied. First it was found that the harmony of a colour palette only weakly correlates with the quality of a website. This correlation increases when only darker colour palettes are used. Next a method was proposed to extract the colour palette from a website. This novel method takes the saliency of the pixels in a website into account. Lastly, the palettes extracted using this method were utilized to propose a model to explain the relation between colour use and quality of websites. Sixty-one different features were tested using three different methods of feature selection. The accuracy achieved in the best model was low. Future work is suggested to improve on this, which should focus on identifying more relevant features and training the model using a better database.