The Institution of Electrical Engineers produces a fact-sheet on colour vision for prospective entrants. The following is quoted from that.
“Colour coding is widely used in the electronics and electrical engineering industries, and has particularly significant safety connotations. At the domestic level, the changes in colour coding of wires for electrical appliances, introduced in the 1960s, was introduced partly to make a used by colour deficient people safer.
Colour coding is used to differentiate the magnitude of resistors and capacitors, whilst in the telecommunications industry, extensive use is made of colour-coded wires. Errors in identification can have serious consequences.”
The IEE claims that electricians and telecoms engineers are routinely screened for colour vision defects. It is thought that BT gives prospective engineers an occupational test involving the matching of coloured wires, but we have been unable to confirm this.
Trainee electricians undertaking an apprenticeship through the Joint Industry Board of the Electrical Contracting Industry are required to produce a medical certificate, which includes a colour vision test or are tested using the City University Test.
