Luminous color used in architectural settings impacts our perception of space and ambiance. With light emitting diode, solid state lighting technology the possibilities of customizing light spectra are manifold, and colored light can be mixed and matched using a variety of different spectral compositions. We conducted several experiments at architectural scale to explore whether stimuli closely matched for chromaticity and light level would produce recognizable differences in visual and visceral qualities.Study 1 used qualitative research methods; during the experiment, participants were free to walk from one illuminated space to another to compare conditions close-up and from afar. Study 2 used quantitative research methods; participants were situated in a fixed viewing location and responded to a questionnaire that was designed based on the responses from Study 1. In Study 3 blood pressure was measured in response to all of the lighting conditions.Overall, the results showed that subjects perceived differences in the visual qualities of the conditions. The results also showed significant differences in affective qualities and physiological responses between some of the conditions.