Unique illumination to bring out the attractiveness of plant colour with white light sources of various spectral distributions

Abstract

Colour illuminations are able to give physically different colours to illuminated objects. But perceived colour changes of objects are not so effective because we have colour constancy. On the other hand, if the colours of the objects have changed without light source colour change, we should believe that colour appearance changes are the changes of objects colour themselves and colour change would be very impressive. We can realize this situation if we design appropriate combination of spectral distribution of light sources and spectral reflectivity of objects. In this study, we investigated colour changes of plants under the white illuminations with various spectral distributions. As the results of the experiments, we can find out various and distinct perceived colour changes of flowers and leaves under certain combinations of illuminations and plants. If we use this illumination technique to the flower arrangement lighting or to the lighting of the garden, we can enjoy another colour world of plants.