Slash, kinda curious too, why purple for Nole and Edberg?
Edberg doesn't quite have purple. It has a unique shade of pink. His color is due to a combination between the best serve-and-volley of all time and the ability to use the opponent's power in strokes against him. Nole's color is also unique, because of his extremely efficient and deadly power defense, which can easily be modeled into an offensive game. These colors along with orange are at the limit between defensive and attacking game, making the players given these colors quite unique in their ability to play the game.
This is all in my perspective and it would be extremely strange if some people would not think differently.
If you wanna ask about more players, please do.