Why is the bat of table - tennis red and black?

Answer 1

A Table Tennis bat requires one of the sides to have a red rubber and the other to have a black rubber. A player is not required to have the same rubber on either side of the bat such that each side of the bat reacts differently. One side may be a high spin rubber while the other acts as an anti-spin. By making each side of the bat a different colour lets an opponent know how the rubber will react when hit off it.

Answer 2

Table tennis bats are red and black so people can tell which rubber they hit it with. Advanced players play with different types of rubber on each side of their bat. Say,mine with a lot of spin and one without much. People used to have both rubbers the same colour and think there was heavy spin on the ball when their wasn't any. The spectators sometimes abused the players for missing easy shots, so the colours were changed in order for everyone to tell which rubber it bounced off.