Robert Ennis

This study investigates how the single color appearance of iridescent objects varies with shape complexity, viewing angle, and motion, finding that hue similarity in multi-color matches best predicts single color appearance.

This study investigates color matching for three-dimensional transparent objects, finding that observers match mean chromaticity but luminance depends on background and matching element, with some models generalizing better than others.

The paper tests the geometric structure of perceptual color space using midpoint judgments and shows it depends on mental representations, revealing an affine geometry when using opponent-color representations.