Up until 06 May 2022, Digimon cards only existed in single colors, but with New Awakening, that changes. With the debut of true two-color cards already enough to make a big impact on the game, BT8 also packs in the Armor mechanic from Digimon Adventure 02 and the DNA Digivolution mechanic from the same series!
Back as far as set 1.5, Digimon with split Digivolution sources, like Imperialdramon, have existed, but BT8 is the first-time two-color cards have appeared. Acting as both of their colors all the time, instead of under certain conditions, this gives decks the ability to "splash" cards from another color far more easily, and there are now cards that actively reward having multiple colors in play.
Perhaps the most interesting is BlackWarGreymon, which is both black and red. Fitting in at the top end of either a red or black Digivolution stack, the When Digivolving effect checks the colors of the Digivolution sources, allowing you to destroy opposing Digimon or Tamers. While it can technically destroy both if there is a red and black Digimon underneath it, the limitation of total play cost makes that unlikely. But coming from a Hybrid heavy format, any Tamer removal is more than welcome.
The second new mechanic in the set also plays with multiple colors, DNA Digivolve, with Kimeramon making the most of the ability. As a Level Five, 8000 DP Digimon, the four Digivolution cost seems hard to justify, but by combining two Level 4 stacks, it becomes possible to DNA Digivolve for free! Not only that, but Kimeramon provides both flexible removal with the DP reduction effect, but also fantastic aggression at 12000 DP if there are four or more colors underneath it. In fact, Kimeramon provides such good value that it forms a large reason why Eyesmon became limited since purple decks were otherwise able to for from no board to a Level Five in play for no memory.
The other Level Five DNA Digivolution cards in the set are also worth looking at, as they provide some niche flexibility to their colors. Both featuring yellow, Silphymon, and Shakkoumon overlap with red and blue, respectively. Silphymon plays off yellow's ability to reduce DP, but the Inherited Effect can also give red a consistent way to remove small Digimon. Shakkoumon gives access to Recovery +1 to blue, allowing what has previously been seen as an aggressive color push into the long game.
Most of the Level 4 two-color cards are also part of the Armor Digivolutions, which offers cheaper Digivolution from specific Digimon, but also the Armor Release mechanic. If a Digimon with Armor Release would be deleted, you may instead choose to trash the top card of the stack to prevent the Deletion. This effectively creates sticky Champion bodies and allows the Rookie to digivolve again. By taking a toolbox approach with the available Digimon, such as Flamedramon and Magnamon, and the suite of Option cards in the set, the deck is equipped to handle anything.