[ London Times ]
This newspaper, most correctly known simply as The Times, began publication in 1785 and continues to this day.
The November 22, 1819 edition of The Times carried the following "lost dog" notice regarding a Newfoundland puppy; interesting here is that the color description is very close to that of the modern Newfoundland, but the fact it merited describing in 1819 further supports the idea that in pre-Victorian times, typical Newf coloration was something other than mostly black:
LOST, a NEWFOUNDLAND DOG PUPPY, on the 12th of November last, about 4 months old; the feet, the end of the tail, breast, and belly, white, and the rest of the body black; answers to the name of Guard. Whoever will bring the same to Mr. Oven's, 23, Birchin-lane, Cornhill, shall receive HALF a GUINEA REWARD.