Colour and gloss
Past colour vision research mostly employed simplified stimuli where objects were typically two-dimensional, matte and uniformly illuminated by a single light source. Whilst such stimuli allow careful experimental control, they lack some of the important features of surfaces and illuminants that potentially offer cues to enable human colour vision.
We're trying to understand mechanisms of human colour vision in more realistic set-up where the objects are three-dimensional and glossy, and lighting environment can be complex.