The tools are both the lamps and the lens.
This shot is looking into my KM 17-35mm lens showing the reflections of a set of three round lamps on a single fixture (more or less above the lens) that provide light in the room where I have my computer. The light from the lamps is white. The output here was subject to the white balance I chose when converting from RAW and has had some curves adjustment, but is pretty true to the colours from the scene I photographed, so no trickery involved.
Lamps and lenses are both useful photographic tools. In this case, the lens also doubles as another tool, ie a somewhat unique mirror. The reflections give a sense of the multi-element structure of this particular lens. They also show how lens elements and their coatings can shift the wavelengths of light from different angles, at least from the outside of the lens, although of course the angles are much more constrained from inside the lens to the camera so that these dramatic colour shifts can't occur. The reflections are at different distances from my camera, based on which lens element they reflect off, so I chose a narrow aperture for reasonable DOF and focused where I though I'd get the best overall mix of sharp reflections for this image.
