JS History 1

When Moroni first appeared to the Prophet Joseph Smith, the prophet records -

...I discovered a light appearing in my room, which continued to increase until the room was lighter than at noonday, when immediately a personage appeared at my bedside, standing in the air, for his feet did not touch the floor.
31 He had on a loose robe of most exquisite whiteness. It was a whiteness beyond anything earthly I had ever seen; nor do I believe that any earthly thing could be made to appear so exceedingly white and brilliant."  (Joseph Smith—History 1:30–31)

Even during the light of day, the Prophet recorded that Moroni -

"...I looked up, and beheld the same messenger standing over my head, surrounded by light as before..."  (Joseph Smith—History 1:49)

Obviously, when they say "lighter than at noonday", the light then exceeds greater.