(Pseudo-)Double Cream Fange

Colour Group: Brun Base, Cream, Fange, Noir Base, Pearl, and Rouge Base
Rarity: Unnatural
Importable?: Yes

Or

Colour Group: Pearl, Rouge Base, and Rouille
Rarity: Unnatural
Importable?: Yes

Cuivre

Colour Group: Rouge Base and Rouille
Rarity: Unnatural
Importable?: Yes

Palomino Chocolat

Colour Group: Chocolat, Cream, and Rouge Base
Rarity: Unnatural
Importable?: Yes

Atlantic

Colour Group: Mer and Rouge Base
Rarity: Unnatural
Importable?: Yes

Atlantic - Mer on Rouge Base

Brine

Colour Group: Cream, Mer, and Rouge Base
Rarity: Unnatural
Importable?: Yes

Brine - Mer on Palomino Base

Shallows

Colour Group: Cream, Mer, and Rouge Base
Rarity: Unnatural
Importable?: Yes

Shallows - Mer on Cremello Base