C#

private void SetButtonColor(object sender) {

   this.Button_headers.BackColor = (sender.Equals(this.Button_headers) ? Color.Blue : Color.White);
   this.MySecondButton.BackColor = (sender.Equals(this.MySecondButton) ? Color.Blue : Color.White);
   ...
}

private object lastButton;
private void SetButtonColor(object sender) {

   if(lastButton != null && lastButton != sender)
   {
       lastButton.BackColor = Color.White;
   }

   sender.BackColor = Color.Blue;
   lastButton = sender;
   ...
}

Quoted from the sample:

"Before a screensaver appears, Windows creates a new virtual desktop for it. The screensaver process is created on this second desktop, which is never locked. Any other processes that the screensaver creates will inherit this virtual desktop, [...]"

I are Troll

foreach (Team team in teams) {
    foreach (Player player in team) {
        ... whatever
    }
}

// where
public class Player {
    string lastName;
    DateTime DOB;
    ...
}

public class Team : List<Player> {
    ... you don't need much code in here, as you can use all the methods inherited from List,
    ... e.g. you can do Team.Add(new Player());
}

; comments start with this special character (choose one)
; whereas keywords start with another special character (choose one)
; $TEAM is a keyword, it is followed by the team name
$TEAM red
; players are listed: firstName; lastName; ...
Jan;Van den Broeck; CB; 88
Gill;Bates; ZZ; 00
$TEAM blue
...
; end-of-file marker
EOF