Flowers produce variations in color saturation by arranging petals at oblique and varying angles

Large color variations can be observed across the face of a flower even when individual petals are the same color. We investigated whether these color variations could be explained by a model that incorporates multiple reflections of light between petals and transmissions of light through petals before the light returns to the observer. The three flowers that we selected for the study exhibited large color variations across the face of the intact flower but had no significant observable difference in color saturation across a single petal or between petals when petals were removed from the flower. We used a spectroradiometer to measure the spectrum across the faces of intact flowers and across individual petals. The measured spectra for all of the flowers were consistent with the proposed model. (C) 2000 Optical Society of America [S0740-3232(00)00105-8].