'Brightness' in the Bible

Six days later, Jesus took with Him Peter and James and John, and led them up on a high mountain by themselves. And He was transfigured (changed in form) before them [and began to shine brightly with divine and regal glory];

who appeared in glory, and were speaking of His departure [from earthly life], which He was about to bring to fulfillment at Jerusalem.

Now Peter and those who were with him had been overcome with sleep; but when they were fully awake, they saw His glory and splendor and majesty, and the two men who were standing with Him.

But since I could not see because of the [glorious intensity and dazzling] brightness of that light, I was led by the hand by those who were with me and came into Damascus.

at midday, O King, I saw on the way a light from heaven surpassing the brightness of the sun, shining all around me and those who were traveling with me.

And He who sat there appeared like [the crystalline sparkle of] a jasper stone and [the fiery redness of] a sardius stone, and encircling the throne there was a rainbow that looked like [the color of an] emerald.