A method is described for estimating the reflection components of glossy objects when the color signal is a mixture of body reflection, interface reflection, and interreflections. The objects are dielectric materials. We first model interreflection between two surfaces. Next, an algorithm is described for estimating the reflection components from a single color image. This estimation is performed in three steps of estimating illumination, object colors, and body interreflection. A chromaticity plane is introduced for analyzing the interreflection effects. We propose an algorithm for separating the measured image into the reflection components. The feasibility of the method is shown in experiments.