Yellow
Yellow is the shade of his madness. His Insanity, his instability. The slightest thing could set him off, and he could tumble off that precipice into absolute insanity, no going back. He fears that day, when he can't come back, when even his Alice can't call him back. He can't always stop it, but he can try. If someone can head him off before he becomes violent, he feels safe. But they can't always get there in time. Each bout of violent insanity is another step closer to that edge. He prays she can save him before its too late.