Red Colour Coding for TOP SECRET Outlet Boxes
TOP SECRET wall outlet boxes should be painted red for easy identification.
Plain language
This control requires that wall outlet boxes used for TOP SECRET information be painted red to make them easy to identify. This is important because if someone accidentally connects a regular device to a TOP SECRET outlet, it could lead to sensitive information getting released by mistake.
Framework
ASD Information Security Manual (ISM)
Control effect
Preventative
Classifications
TS
ISM last updated
Nov 2021
Control Stack last updated
19 Mar 2026
E8 maturity levels
N/A
Section
Cabling infrastructureTopic
Wall Outlet Box ColoursOfficial control statement
TOP SECRET wall outlet boxes are coloured red.
Why it matters
Misidentified TOP SECRET outlets can lead to unauthorised data breaches if users connect devices to the wrong (non-TOP SECRET) outlet.
Operational notes
Regularly inspect TOP SECRET outlet boxes for wear, repainting, or graffiti that could obscure the required red colour coding and confuse users.
Implementation tips
- The facilities manager should arrange for a professional painter to thoroughly paint the outlet boxes red. This ensures that the outlets are clearly distinguishable to prevent accidents.
- The IT team should label each TOP SECRET outlet once it is painted to reinforce its purpose. They can use bold labels stating 'TOP SECRET ONLY' to avoid confusion.
- The office manager must update internal maps and documentation to clearly indicate which outlets are designated as TOP SECRET. This helps in case repairs or checks are needed.
- Security personnel should be trained to recognise the red outlets and understand the importance of their use for TOP SECRET connections only. A short briefing can clarify what needs to happen if they spot a non-compliant setup.
- The procurement team should ensure that maintenance contracts include a provision for checking the paint condition of these outlets during routine checks. This helps keep the marking standards consistent over time.
Audit / evidence tips
- AskThe outlet maintenance logs: Request any records for maintenance checks specific to the red outlets GoodShows regular checks with no missed appointments
- AskTo see the internal guide map for office outlets: Request the document or system where the TOP SECRET outlets are labelled GoodShows every red outlet accurately labelled and updated within the last year
- AskDetails of any training sessions regarding the recognition and importance of red outlet boxes GoodIncludes a list showing high attendance and detailed, relevant content
- AskTo see procurement contracts: Review contracts with maintenance companies to ensure they include red outlet checks GoodIncludes scheduled painting and checks written into the contract terms
- AskThe outlet inspection report: Request this document to see recent inspection findings on the red outlets GoodWill have notes about outlet conditions and any improvements needed
Cross-framework mappings
How ISM-1721 relates to controls across ISO/IEC 27001, ISO/IEC 42001, Essential Eight, and ASD ISM.
ISO 27001
| Control | Notes | Details |
|---|---|---|
| handshake Supports (2) expand_less | ||
| Annex A 7.6 | ISM-1721 requires TOP SECRET wall outlet boxes to be coloured red for clear identification in secure spaces | |
| Annex A 7.8 | ISM-1721's requirement for red colouring on TOP SECRET outlet boxes aids in their clear identification, preventing accidental misuse | |
These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.