Colour Blind Electricians: What You Can (and Can’t) Do in the Trade 

Short answer: yes, many do. But here’s the thing, you’ll need to understand how colour vision is assessed in the trade, where it actually matters most, and how to work safely and accurately without relying on colour alone. 

This guide explains the rules, the workarounds, and the training routes that keep your career options open, whether you’re starting out or moving towards your NVQ Level 3 Electrical, or upskilling into low-carbon roles via our EV installation course this article will help to explain the best place to start. 

What Colour Blindness Means in Practice 

Colour vision deficiency (CVD) ranges from mild to severe and most commonly affects red-green discrimination. In real jobs, this may crop up when: 

• Identifying legacy cable colours (e.g., red/black/green) versus modern harmonised colours (brown/blue/green-yellow) 

• Reading multi-core control cables and certain data/telecoms pairs that rely on colour codes 

• Working with resistor colour bands (rare in installation work, common in electronics) 

• Picking out indicator LEDs (red/green/amber) on devices and panels 

Here’s the key point: safe, compliant work doesn’t rely on colour alone. You’ll be trained to confirm identity by position, marking, and test results (continuity, polarity, impedance), not just by looking at the sheath. Honestly, even electricians with perfect colour vision shouldn’t be guessing based on colour, tests are what actually prove things. 

Industry Requirements (Plain-English Version) 

The Joint Industry Board (JIB) sets medical standards for apprentices and graded electricians. For apprentices, JIB normally expects normal colour vision, evidenced by recognised tests such as Ishihara or CAD. If you don’t pass Ishihara, a pass on a CAD (Colour Assessment & Diagnosis) test can still demonstrate functional colour recognition for safe electrical work. 

What this means for you: 

Don’t self-exclude. Many candidates who fail a simple Ishihara screening can still pass a CAD assessment that’s more job-relevant. Like, the Ishihara test is quite harsh, it’s not the be-all and end-all. 

Be upfront, early. Tell us at application stage so we can advise on the most suitable test pathway and training plan. Honestly, it’s way easier to sort this out from the start than halfway through. 

Case-by-case support. At Elec Training, we review individual results and the type of work you aim to do, then map a pathway toward competence without compromising safety. We’re not here to gatekeep, we’re here to find solutions. 

Where Colour Really Matters (and How to De-Risk It) 

1) Legacy Colours & Mixed Installations 

Older UK installs use red (line), black (neutral), and solid green (earth). Modern installs use brown, blue, and green/yellow. On refurbishments or extensions, both may appear, which is honestly confusing even if you’ve got perfect colour vision. 

Workaround: Verify by testing (continuity/polarity), check terminal position, and apply clearly printed markers or sleeves before you reconnect. No guessing, ever. 

2) Multi-Core and Control Wiring 

Some control cables use dense colour codes, which can be a nightmare if you’ve got CVD. 

Workaround: Number ferrules or use engraved markers. Follow drawings that reference core numbers rather than colours. Cross-check by ringer tests. Basically, make the system idiot-proof (and I mean that in the nicest way possible). 

3) Panel Indications 

Reds, ambers, and greens can look similar with certain CVD, and to be fair, even in poor lighting they can trip up anyone. 

Workaround: Choose devices with symbols/text or different flash patterns as well as colour. Label pads. Rely on the alarm code, not just lamp colour. 

4) Lighting & Switching 

CPCs and switched lines must never be identified by colour alone. This is true for everyone, not just people with CVD. 

Workaround: Sleeve correctly, prove dead, test every time, and record your results on the certs. Document everything. 

Practical Strategies That Actually Work on Site 

Test, don’t guess. Prove identity with your meter, continuity, polarity, and R1+R2 beat eyeballing any day. This should be your mantra. 

Mark everything. Use numbered ferrules, printed heat-shrink, or tagged labels so you and the next person can read the same story. Future you (and the next electrician who works on it) will thank you. 

Prefer high-contrast kit. Choose testers with large fonts/bar graphs and devices whose terminals are physically keyed and clearly mould-marked (L/N/PE). Makes life so much easier. 

Adopt a consistent method. Same test sequence, same labelling convention, same photos for your portfolio and EIC/EICR evidence. Consistency is your friend. 

Use documentation. Good drawings, schedules, and certs reduce reliance on memory and colour — and they also strengthen your NVQ evidence set. Win-win. 

Buddy checks for first-fix. On complex multi-core looms, a quick second set of eyes avoids mix-ups at the panel. No shame in asking for a double-check. 

Training Routes That Keep Doors Open 

1) Entry to Work and Your NVQ 

If you’re starting out, your aim is to build toward the electrical NVQ Level 3 (with AM2 at the end). That portfolio is evidence-based, photos, test sheets, risk assessments, not colour-matching exercises. Your assessor will care that the installation is safe, tested, and compliant, with the right identification in place. 

On programme, we’ll help you standardise your labelling and test evidence so colour is never your only identifier. 

2) Choosing Early Specialisms 

If your colour vision is borderline on Ishihara but you pass CAD (or you simply prefer low-risk, structured wiring), consider roles where numbered identification is the norm: 

EV charge points (domestic & small commercial). Devices have clearly marked terminals and manufacturer-specific step-by-steps. Commissioning relies on test values and app readouts rather than colour judgement. Our EV installation course is a smart first upskill once you’re confident with inspection and testing. 

Distribution & containment (tray, trunking, conduit). The work is about routes, supports, and correct terminations, inspection and torque values trump colour recognition. 

Data cabling & smart tech with numbered pairs or labelled terminals. You’ll punch-down to standards and test with certifiers. Honestly, this is one of the easier areas if you’ve got CVD. 

3) Build Your Testing Confidence 

Colour confusion reduces as your testing discipline increases. Consider adding (or preparing for) inspection and testing training as soon as you’re comfortable with fundamentals. Being method-driven keeps you accurate whatever your colour vision looks like. 

Safety, Compliance, and Your Rights 

Safety first: Even with perfect vision, no electrician should rely on colour to prove identity on live or dead circuits. Colour is a hint, tests are the proof. Let’s be real, assuming anything in electrical work is dangerous, full stop. 

Workplace adjustments: Many employers are happy to make reasonable adjustments, for example, ensuring drawings reference core numbers, specifying kit with text/shape indicators, and agreeing team checks on certain tasks. It’s literally their legal obligation under the Equality Act, but beyond that, most decent employers genuinely want to help. 

Be professional about it: Tell your supervisor how you prefer to mark and verify conductors. Clear method statements and consistent labelling help everyone, and look excellent in your NVQ portfolio. 

FAQ 

Will colour blindness stop me getting an apprenticeship? 

Not automatically. You’ll usually be asked to complete a colour vision assessment. If you don’t pass Ishihara, request a CAD test. We’ll advise on the best route based on your results. 

Can I still reach fully qualified status? 

Yes, provided you meet the JIB colour vision standard (typically via Ishihara or CAD), complete your NVQ Level 3, and pass AM2. Your evidence is about safe, correct work, not colour spotting. 

Which tasks are trickiest with CVD? 

Legacy cable colours, some multi-core control wiring, and panel indicators. All can be managed with numbered identification, good drawings, and test-led methods. Honestly, nothing’s impossible, it just requires being methodical. 

What should I buy for my toolkit? 

A tester with a clear display and audible cues, a good label/ferrule kit, fine-tip markers, and a bright head-torch to improve contrast. That combination makes a big difference day-to-day. 

Your Next Steps with Elec Training 

Ready to begin locally? Reach out. 

Colour blindness doesn’t have to short-circuit your ambition. Get the right assessment, adopt test-first working, label everything clearly, and choose training that builds your competence step by step. We’ll help you design a pathway that’s safe, compliant, and rewarding, because honestly, the industry needs good electricians, and colour vision is just one small piece of the puzzle.