Condition green, condition yellow, condition red – colors aren't just for traffic lights and terrorism warnings; they also guide how street departments handle plowing. In Spokane, green means monitoring wet roadways. Yellow brings deicing trucks to slick roadways, freezing rain conditions and up to 2 inches of snow. Any more snow than that, and crews go into red mode, using snowplows to clear streets, said Engineering Department spokeswoman Ann Nolan.