This guide covers what the standard allows, where each colour tends to be asked for, and how colour affects your branding.
What the standard allows
EN ISO 20471 recognises three fluorescent background colours: yellow, orange-red and red. Each must meet set colour and brightness limits when tested, and keep them after the stated number of washes. Most garments sold in the UK are yellow or orange.
The standard treats the colours as equal for visibility class. Choosing between them is about where you work and what the client asks for, not about one being safer in every setting.
Where orange is expected
Rail is the clearest case. Work on Network Rail infrastructure calls for orange clothing to the railway group standard GO/RT 3279, and yellow is not accepted trackside. If your team does any rail work, buy orange that is marked to that standard, not just any orange hi-vis.
Some highways and utilities clients also specify orange so their crews stand apart from the public and other contractors. Contracts vary, so check the client's rules before ordering.
Where yellow is the usual choice
Yellow is the default on most building sites, warehouses, ports, car parks and delivery rounds. It shows well against grey concrete, tarmac and overcast skies, and visitors' vests are nearly always yellow, so it reads as 'site' to everyone.
Some firms use both: yellow for general staff and orange for a specific role such as banksmen or traffic marshals. That works only if every site you visit is happy with it.
Matching the background you work against
Think about what is behind your workers. Orange can stand out better against green fields, hedges and autumn leaves, which is why some grounds and forestry teams prefer it. Yellow can struggle against bright yellow plant or cladding. If your site rules allow a choice, stand a worker in front of the real background and look from a distance.
Colour and your logo
A logo in your brand colours can look very different on fluorescent yellow than on orange. Dark navy, black and dark green print clearly on both. Pale colours, white and some reds can vanish on orange. Wherever it goes, the logo must sit on the fluorescent fabric only, never on the reflective tape, and a big print can reduce the compliant area.
Where to put your logo
Print is the usual method on hi-vis of either colour. Choose a one-colour version of your logo in a dark shade so it stays readable on both yellow and orange, and keep it to the left chest and a modest back panel between the tape. If you run mixed colours, use the same logo artwork on each so the team still looks like one company. You will get a proof to approve showing the logo on the actual garment colour.
