Unleashing the Full Spectrum: Red, Blue, and Purple Teaming in Penetration Testing

The language of colours in security operations borrows from military wargaming: attackers wear red, defenders wear blue. The distinction is useful shorthand, but it often obscures more than it reveals, particularly when organisations run red team exercises without a functioning blue team capability to learn from them.

Red teaming

A red team engagement goes beyond a standard penetration test. Where a pentest is typically scoped to specific systems or a specific period, a red team exercise simulates a real threat actor campaign: reconnaissance, initial access, persistence, lateral movement, and objective completion.

The value is not just in finding vulnerabilities - it is in testing whether your detection and response capability actually works under realistic conditions.

In a physical context, red teaming might involve multi-day reconnaissance, building-specific pretexts, and attempts to reach a defined objective (a server room, an executive floor, a document store) without triggering an alert.

Blue teaming

Blue teams are the defenders: monitoring, detection, incident response. Their job is to identify and contain threats. In practice, many blue teams spend most of their time on alerts and have limited opportunity to practice against realistic adversary behaviour.

The gap between what an organisation believes its detection capability is and what it actually is tends to be significant. Red team exercises surface that gap.

Purple teaming

Purple team exercises run the red and blue teams together - not as adversaries, but as collaborators. The red team attempts a technique; the blue team observes whether they detected it and, if not, why not. Detection gaps are closed in real time.

This model accelerates learning dramatically compared to a traditional red/blue engagement where the debrief is the only knowledge transfer point.

What this means for physical security

The same logic applies to physical security testing. A physical penetration test that simply delivers a list of findings is useful. A test that also observes how staff respond - whether challenges happen, whether security is notified, whether an incident is raised - is significantly more useful.

The findings from the human and process layer are often more actionable than the findings from the physical controls layer.