A fixture for through hole mounting to a panel includes a flange structure fabricated of a translucent material. The flange structure includes a body portion adapted to extend through a mount hole in the panel and having a outer peripheral portion, and a transverse flange portion having an outer size larger than the hole opening. A periphery flange portion overlaps the panel surrounding the hole when the flange structure is installed in the panel hole. A light source attachment portion is configured to direct light emitted from a light source into the body portion of the flange structure, so that at least some of the emitted light passes into the flange portion to illuminate the flange portion.