Deck Colour???

[Nightshade101]

What does deck coliur mean?

[Skorpius]

There are 4 card packs you can choose after you win or lose a battle. Each color has a certain percentage for each type of card.
Blue has a better chance at more Creature Cards per pack.
Red has a better chance at more Item Cards per pack.
Green has a chance of more Action Cards per pack.
Black as a rounded chance of whatever card.

There are guides for this, though, and it's better to look before asking.