The images captured by a digital camera do not depend only on the characteristics of the objects in the scene but also on the colour of the scene illumination. To account for this confounding influence various colour invariants have been introduced whose aim is to provide descriptors that do not change with a change in light. In this paper we evaluate the usefulness of these invariants for general purpose content-based image retrieval. The results show that the application of invariants may lead to a severe degradation in retrieval performance.