From the Nationals (emphases mine): "The Washington Nationals have partnered with Planet Green, Discovery's new 24-hour eco lifestyle and entertainment channel, for a 'Get Your Green On' promotion on Wednesday, June 4 when the team takes on the St. Louis Cardinals. All fans attending that evening's game are encouraged to wear green and participate in the night's promotion.The first 5,000 fans who exit the Navy Yard Half Street MetroRail Station will
receive a loaded farecard for their trip home. Fans who enter
the ballpark via Half Street, SE will
walk up a green carpet to the Center Field Gate.
Nationals players and ushers will don green hats for the night and the Nat Pack & Racing Presidents will sport green t-shirts. Nationals fans will benefit from
'Random Acts of Greenness' throughout the game.
"Planet Green will flip the switch to their new programming from Nationals Park at 6:00pm. Discovery President & CEO David Zaslav will throw out the ceremonial first pitch from the green pitching rubber. Capital Blend, an a cappella group comprised mostly of Discovery employees, will perform the National Anthem. The line-up card delivery to the green ceremonial home plate will be handled by Eileen O'Neill, Planet Green President and General Manager. Emeril Lagasse, star of Planet Green show Emeril Green, will start the game by announcing 'Washington--Let's Play Ball'.
"Nationals Park is the only LEED-Certified sports venue in North America."