Here's the USA Track & Field rule on using the colored flags to mark cross country courses:
quote:
from USATF Competition Rules
Rule 251 Course (page 136)
2. The course must be clearly marked, preferably with red flags to indicate a left turn, yellow flags to indicate a right turn and blue flags to indicate continuing straight ahead. All flags must be visible from the point where the runner passes the previous flag, with a maximum interval of 50m. A white chalk line should be marked on the ground the entire route for the athletes to follow. Each kilometer point should be clearly recognizable. The course should be laid out so that there are no sharp turns at the beginning of the course and so that it is not less than 9m (approximately 10 yds.) wide at any point.
Thank you. -- Justin