Why are the uniforms of table tennis referees all blue?

Like previous large-scale table tennis competitions, the uniforms of table tennis referees are red and blue, but referees appearing in the competition area must wear them.

The duties of table tennis referees are:

1. Check the acceptability of competition equipment and conditions, and report to the referee if there are any problems;

2. If the players of both sides can't reach an agreement on the game ball, they can decide a game ball at will;

3. Presided over the lottery to decide the serve, receive the serve and orientation;

4. When the athlete can't abide by some regulations of legal service due to physical disability, the referee will make a ruling;

5. Control the orientation, serve order and receive order, and correct the above mistakes;

6. Decide to score or serve again in each round;

7. Score according to the prescribed procedures;

8. Execute the rotation serve method at an appropriate time;

9. Keep the continuity of the game;

10. Take action against those who violate the guiding behavior regulations.