Abstract: This document discusses, among other things, contrasted components for a medical device, and methods of making and using contrasted components. An example device includes a header including an opening configured to receive a set screw and a plug, and an insulative component, such as a plug or sleeve, that is insertable in the opening over the set screw. The insulative component has a visible exterior surface that is visually contrasted from a portion of the header proximate the opening. An example method includes forming from a first material a medical device header block having an opening configured to receive a plug, adding a marker to the first material or a second material, and forming from the second material a plug insertable in the opening. The marker in the second material creates or enhances a visual difference between the first material and the second material.