Talk:Sideboard/@comment-8031082-20140608121726/@comment-26290163-20170815073753

I second that. The Floor Rules stipulate one color for the cards that are played (sideboard and main deck), and they must have an opaque back. However, the Flag can be a different color from the Deck and Sideboard (not the Buddy). There's a few other stipulations about Sleeve Designs, but that's the gist. Here is a link to the Latest Floor Rules.

http://bushiroad.com/en/wp/wp-content/uploads/Bushiroad-Floor-Rules-106.pdf