It’s usually just a standard spotlight, not a special model with a built-in blue edge. The thin blue ring is most likely caused by chromatic aberration and other lens imperfections in the spotlight’s front optics.

A spotlight lens is meant to collimate the lamp’s light into a more controlled beam, but simple, heat-resistant lenses used in many spotlights are not perfectly corrected. As a result, different wavelengths of light can bend slightly differently, producing a colored edge—often blue—around the beam. The effect can vary depending on focus, beam width, distance to the subject, and the light’s aperture/iris settings.

So the blue ring is generally an optical artifact of the spotlight lens rather than the name of a particular light type.