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Railway Orange

Railway garments must not only be orange; they must be a specific shade of orange. As Hivizology specialists we take a look at the why this is, and how we achieve it.

All UK and EU professional high vis must meet the colour requirements of the international standard, ISO 20471. This specifies that either fluorescent orange, yellow, or red must be used.

If yellow and red are sufficiently luminous to meet the safety standard, why aren’t they used on railways?

There are a few reasons why orange was chosen.

Though red’s a popular colour for high vis in Europe, it doesn’t offer the same luminosity as yellow or orange. Working in low light conditions, red fails to provide the same calibre of protection as the other two colours.

So why not yellow? It’s even more luminous than orange and is commonly used in roadwork and construction. But it doesn’t contrast quite as well as orange against lighter backgrounds. If railway workers are to be seen against a green field, orange will be more conspicuous than yellow.

It was probably also a consideration that orange looks less like the green ‘Go’ light, reducing the risk of driver confusion.

So, when the British Railway Standard GO/RT 3279 was introduced in 1994, it required all rail garments to use orange fabric. In 2016 this standard was replaced by RIS-3279-TOM, but the fabric colour has remained the same.

RIS-3279-TOM requires the fabric used to manufacture hi vis to meet specific chromaticity coordinates. The Colourific Values Chart below illustrates the requirements of the standard.

The yellow, orange, and red blocks show the acceptable ranges of each colour to meet the ISO 20471 professional high visibility standard.

Zooming in on the orange and red, we see the RIS-3279-TOM box displaying the accepted range of orange for railway use.

The blue dot represents the RIS-3279-TOM target colour. When dying fabrics, this is what we’re aiming for.

To explore Leo Workwear’s innovative range of RIS-3279-TOM conforming products, visit


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