Swiss railway workers have been told to change their orange reflective vests to prevent Dutch football fans following them onto the tracks.
"We have now given out yellow vests to all our staff who have to work on or cross the tracks in Basel, where the Dutch fans are now based," Oliver Tamas said on Friday.
"It has raised a few eyebrows but we think it's a necessary measure to ensure the safety of our guests."
Tamas said that 1,500 railway staff involved in fan coordination work had already been given yellow vests to help them stand out from the Dutch supporters.
Police in Berne also ditched their orange vests after Netherlands were drawn to play all three of their group stage matches in the city.