Tort colors 
(Tort (or tortoiseshell), blue tort, chocolate tort, lilac tort.  

To be a tort you must have self (aa) and  non-extension (ee) this is the same gene that makes the pearls have color only on ears, feet and nose.
Tort aa B? C? D? ee
Blue tort aa B? C? dd ee
Chocolate tort aa bb C? D? ee
Lilac tort aa bb C? dd ee