Here is the summary of a few rules for equipment and attire commonly applied in table tennis competitions in Singapore as at the end of 2017.
1. Three-star size 40+ white balls are used
2. White attires are not allowed
3. It is the responsibility of each player to ensure that racket coverings are attached to their racket blade with adhesives that do not contain harmful volatile solvents
4. Playing clothing shall consist of a short-sleeved or sleeveless shirt and shorts or skirt or one-part sports outfits, socks and playing shoes; other garments, such as part or all of a tracksuit, shall not be worn during play except with the permission of the referee
These rules are just for your reference and some competition follow stricter rule and standards.
You may refer to the ITTF Handbook 2017 for the international standards and the complete set of rules.