safety orange
n.— «With the flags standing so high above the hydrants they will be easy to identify, even if they are buried by snow. In addition, the bright orange (commonly called “safety orange” for purposes like these) flags can be easily spotted from a fair distance at night and through moderate fog.» —“Safety flags installed on Keyser hydrants” by Kati Walker News Tribune (Keyser, West Virginia) July 19, 2006. (source: Double-Tongued Dictionary)