Colour in spaces plays an important role on inhabitants’ mood. In interior design colour has been used to decorate spaces in order to lift and change mood in people. It has been already proved that certain colours relax people while other colours have an opposite effect. However, not all the colours have been researched, and especially their effects on teenagers’ moods have not been researched. This paper begins research in this area by presenting the findings of a study seeking to understand how teenage boys relate to colour, and seeking to identify what their favourite colour is. The teenagers completed a questionnaire about colour and the results show white is a dominant choice for bedroom design followed by blue, black, green, violet, red, grey, yellow, and orange. Red and blue were on top as favourite colours, followed by white, purple and green being preferred once each.