The public lobby of Detroit's Guardian Building is illuminated by a 3-story window on the building’s north end and complimented by a window above the Griswold Street entrance (seen here) whose light passes beneath tiered steps of mostly blue terra-cotta, casting a blue-tinted glow of reflected light into the room. The tiered arch of layered terra-cotta is itself a light sculpture, with color and shadows changing as lighting conditions vary outside.
The addition of high intensity incandescent, fluorescent and halogen lighting in more recent years significantly altered the appearance of the building's interior (for which, ironically, an award was given). This is akin to putting lights inside a kaleidoscope to better see the pieces of colored glass. Some thought ought to be given to restoring the interior lighting to its original condition.