7. give away $45,000.*
* at round 4, every player in the minority (whether black or red) will realize that they are in the minority. they will all write their color and receive $5000. the remaining players will then realize they are the opposite color, and at round 5, they will all write their color and receive $5000.
c.t. has shown that while completely trustworthy, he is not a perfect reasoner.