Solid Bengals (also commonly called Melanistic)and have very muted markings. Here are some of the colors available in solid.
(1) Melanistic (Solid Brown)- Melanistic are essentially a black cat. As a kitten the markings are visible, but as an adult most times you are not able to see the markings. Sometimes in certain lighting you can see ghost markings like a black panther has.
(2) Smoke (Solid Silver)
(3) Solid SLP
(4) Solid Mink