Our lab did the same and it is still pink years layer. My vet said it could be tattooed.

tattooed??? you mean let the tattoo make it black again? No…that would be cruel

It is not cruel- it can prevent skin cancer and is done while dog is under anesthesia.

Quote:
Pink noses are accordingly more at risk for the development of cancer. In some cases, an owner can choose to have his dog’s nose tattooed with black ink to protect it from the sun. This practice is more common in dogs such as the Collie who will get nasty ulcerations from sun exposure.
A link on collie-nose. Another ailment that is helped by tattooing

It depends on how deep the scarring is. Superficial wounds may return to the original pigmentation, but it is certainly possible that the color (or lack thereof) is permanent.

My weimaraner had her nose clawed by a cat, and although it bled only briefly, you could see the lines on her nose for several weeks. We kinda joked about it because it was brown with pink stripes during that time. It regained pigmentation however, and now there are no scars.

The 2–3 times my huskies nose has gone pink (twice during winter and once cuz the cat scratched him), it has gone back to normal. Took a bit longer with the scratch, like 2 or 3 weeks maybe? If it persists longer, then you may want to ask a vet.