Color-coding of Badges?

In creating/implementing a multi-location, single-control point Proxi-badge system, what are peoples’ thoughts on whether or not to color-code the badge for visual cues? The individual Proxi-card badges are encoded with access-by-role, but how do people feel about color codes (i.e., red for visitor, blue for onsite security, one color scheme for employees, a similar-but-different color scheme for consultants, etc.)?