Just as Windu is about to overpower Sidious, he unleashes Force lightning at Windu but deflects it back with his lightsaber at Sidious, deforming his face into the wizened, yellow-eyed visage seen in the original films.
He unleashes Force lightning at Windu. He deflects it back with his lightsaber at Sidious. He was deforming his face into the wizened-eyed visage. This was yellow. This wizened. This was yellow. Eyed visage was seen in the original films. This was yellow. Windu is about to overpower Sidious.