Interesting, I had a look into this. From what I have seen brindles don’t fade. Silver brindles still have brindle markings even when they have cleared. Brindle markings are less prominent when the coat is longer and more prominent when short.
I am also wondering about this - we would like to get a brindle and love the striped look. But I suspect that as the dog gets older, the darker stripes would fade in the same way that a solid dark coat tends to. Eventually the stripes would be much less distinct. Is there anyone out there who's got a brindle over the age of 4 or 5 that could comment?
Brindles fade. A black brindle fades to blue, a silver brindle would likely fade to a light silver. They're striking, and brindle naturally occurs in poodles, but I don't know of a reputable breeder who is pursuing this coloring.