The first section of this thesis covers the basics of colour theory and the use of colours in website design, while the second part presents the results of an analysis and comparison of colour schemes used on existing websites. The analysis is based on data collected from forty tech websites and forty restaurant websites. It shows the prevalence of light among desaturated colours and blue among saturated colours on tech websites and the prevalence of dark, primarily brown shades on restaurant websites. No major differences were noted between Slovene and foreign tech websites while the analysis of restaurant websites indicated deviations, but smaller than expected. The tech website colour schemes are mostly complementary or split-complementary, whereas restaurant websites use mainly neutral colour schemes.