I'm not a huge fan of the new unis but I see how they would appeal to a younger generation.
And - as has been said - they are only wearing them for one game. You don't like them, you really don't have anything to worry about.
Just be happy they aren't as bad as the 'Turn Ahead The Clock' uniforms that Major League Baseball made teams wear for a game in 1999.
Anybody remember the 'Mercury Mets'?
http://www.uni-watch.com/2011/07/27/the-worst-uniforms-in-mlb-history/
So just know - it coulda been worse.