Question: Does the Landseer or English Mastiff have a limited range of colors? 

Related documents: [0]  [DOC] The "'Landseer" is a dog breed. The breed is not recognized by all kennel clubs . It is not to be confused with a white and black Newfoundland, which is also often called a "landseer". [END] 
[1]  [DOC] The English Mastiff is a breed of extremely large dog (often known simply as the Mastiff) perhaps descended from the ancient Alaunt and Pugnaces Britanniae, with a significant input from the Alpine Mastiff in the 19th century. Distinguishable by enormous size, massive head, and a limited range of colours, but always displaying a black mask, the Mastiff is noted for its gentle and loving nature. The lineage of modern dogs can be traced back to the early 19th century, but the modern type was stabilised in the 1880s and refined since. Following a period of sharp decline, the Mastiff has increased its worldwide popularity. Throughout its history, the Mastiff has contributed to the development of a number of dog breeds, some generally known as Mastiff-type dogs, or, confusingly, just as "Mastiffs". [END]  
Answer: English Mastiff
English Mastiff