Today, the building sector is one of the greatest energy consumers of the world. Therefore, it is impor-tant that designers think about strategies to save energy at the different stages of the building process,including during its life. Considering that a great deal of energy will be spent in artificial lighting, animprovement in the performance in front of light of the architecture itself could lead to a better vision ofthe spaces, which depends on the quantity and quality of light available and on the architectural char-acteristics as well. One of the most influential aspects is the colour of the space. Here, a case study ispresented in which three coloured spaces were assessed by observers under different lighting condi-tions. Luminance and illuminance measurements were taken to compare these values with the votesgiven. The results query the correlation between measured values and luminosity of three-dimensionalspaces. As a consequence, the choice of a particular colour may increase the sensation of light in a spaceand, therefore, a reduction of energy use in artificial lighting is possible. In addition, architectural designcan take advantage of colour to improve the visual quality of indoor spaces.