Discussion: Use _slightly_ different colours for each bot

[Debilski]

This could be useful for debugging (but possibly also during the real games) in order to distinguish the two bots on each team more easily, but it would likely be a rather noticeable change in how Pelita looks. (And we would have to go into colour science to decide on the proper shades.)

Bonus discussion: Akin to bot.say let the colour change be user-configurable during the game.