He's not talking about the blue and orange, he's talking about the "half crystal, half flesh" motif that is the signature look of Soulcalibur/Soul Edge.
Unless you're saying every movie poster is half-crystal and half-flesh...
I'd sooner chalk this up to the same artists being involved than assume it's tied into SC content somehow.
Alternative short version of this post: Anyone got any stage boss ideas in mind? what series do you think could utilise this new stage gimmick the most?
Mario: Bowser Jr. and/or the Koopalings
Yoshi: something to do with Kamek
Kirby: Heavy Lobster, Kracko, Mr. Sun and Mr. Moon, Dynablade, maybe Nightmare or Marx if they really want to go nuts
Punch-Out: Pick an opponent, any opponent
Sonic: Robotnik in da house
Metal Gear: Metal Gear