School Crossing signs have a yellow or fluorescent yellow-green background, with black designs. The School Crossing sign is used to warn drivers that they are approaching a crossing where school children cross the road. A separate downward-pointing arrow plaque below the sign usually indicates the actual location of the crosswalk. School Zone and School Crossing signs are meant to provide students with a safe zone when they cross the road to and from school.

Source: DMV Permit State