Which of the following is NOT considered a reference point?

A reference point in the context of body repair refers to specific, measurable locations on a vehicle structure that can be used to ensure accurate alignment and repair. When considering what does not constitute a reference point, the color of paint stands out.

Mechanical attachment points, edges of panels, and corners of openings provide physical locations that can be measured and used to determine the structural integrity and alignment of the vehicle. These points are essential during the repair process for ensuring that all components fit correctly and that the vehicle maintains its intended shape and functionality.

In contrast, the color of paint does not serve as a measurable or structural reference. It is more aesthetic and does not provide any information regarding the vehicle's structural alignment or condition. Therefore, it clearly does not fulfill the criteria of a reference point critical for effective unitized structural body repair.