The secret of this is really no secret for those who read the bible.

But.......one must seek Strongs concordance for understanding.

Adam or awdawm is Hebrew for show blood in the face or red.

Meaning.

Adam had or could have rosy cheeks or blush. Since other races cannot do this Adam was white.

Now take the next step.

Jesus was in Adams line. Check Luke and Matthew for verification.

Jesus was white.