i'd wear a shirt with exactly the same colour of my racket... so the opponent cannot see it well
As in, black?
That being said, a vast horde of people are making easy quips about choosing rubber colour to foil opponents. I don't get this. As an old hand at this, having played before the colour restriction rules were established and after, I am very strongly convinced that visual clues play a very, very limited role during gameplay. Making out the difference between the two sides may be somewhat relevant when receiving a serve, but after that it's the sound (maybe) and the flight trajectory (a lot) that tell you how to read the incoming ball.
Especially irrelevant is matching your shirt or the table colour. Or the ball colour. Or the wall colour. You're not hitting with your shirt, the wall, the table. By position, it's pretty obvious what's contacting the ball, and where. I just don't see much room for har-har-har easy cheats here.
The rest is esthetics. Me, I'd really like to play black and black. Using the same rubbers. And not being distracted when neurotically twiddling, feeling forced to correct that during a rally. One distraction less == a solid win, for me. Others may like red. Or another colour, if only for esthetics. I don't need to match my rubber with my handbag or eyeshade; others seem to have such needs, though. Who am I to deny them?