Blue scratch

This morning Evelyn saw that William had a rather large scratch on his leg (I think it was from the rock pile) so I told her that mommy had a scratch too and showed her the one on my hand. To which Evelyn responded "where is my scratch?" she looked all over and could not find a single scratch when she looked at her hand and said "I have a blue scratch" pointing to the vein on the back of her hand.