Color deficiency is a common affliction for males, with about 8% of the male population suffering from some form of – colloquial – color blindness. In common description, this is interpreted as the inability to perceive certain colors from a sensory standpoint. If that description is sufficiently complete, spatial attributes of the color signal should not influence the visual experience of a Color Deficient Observer (CDO).In this paper we describe the set-up and results of an experiment that is intended to vary the spatial attributes of a color deficiency test when shown to an observer. For this, we modified color vision charts to maintain their colorimetric attributes while varying spatial attributes and we measured color deficient observers with respect to their response accuracy and their response speed. We show results that indicate that there is a clear influence of color proximity in the responses.