﴿ وَنَزَعَ يَدَهُۥ فَإِذَا هِىَ بَيْضَآءُ لِلنَّٰظِرِينَ ﴾

“and he drew forth his hand - and lo! it appeared [shining] white to the beholders.”

Then he drew out his hand he brought it out of his pocket and lo! it was white glowing before the onlookers and not its usual skin colour.