what colour are the reflective studs on a motorway

On a UK motorway, the colour of the reflective studs depends on where they are:

• Between the lanes on a motorway: white studs.

• Left-hand edge of the carriageway / between hard shoulder and first lane: red studs.

• Right-hand edge by the central reservation (middle barrier): amber studs.

• Between the motorway and its slip road or at lay-bys: green studs.

• Temporary lane layouts (e.g. roadworks): fluorescent green/yellow studs.

So if you’re specifically revising the classic UK theory-test question “what colour are the reflective studs between the lanes on a motorway?”, the answer is white.