Yes, they can change their color a bit, add spots, change the shape of current spots – it’s strange to see. Spockie was a lovely gray when I got him, and he gradually got darker. Finally one of my family said “didn’t he used to be gray?”
I advocate the Hair Buster Comb and/or a brush as well. It helps a lot to comb and brush him several times a day until it’s almost over. It should be soon since he’s been shedding 4 weeks and you’re at the major fur loss stage. Not to worry.
The little bits that you can pluck are tempting to pick off. Just be very gentle so you know that it’s already detached instead of pulling them out if you meet with some resistance. It will be ready to pluck off within a very short time anyway. They sometimes have a little black bit at the tip, like a root bulb only tiny. He likes the grooming help, so continue to do it. Also, you can wet your hands and rub them across him to get more fur off.
Be sure he gets lots of water and hay to keep his digestion moving. He will probably pass some poos that are strung together like pearls. That’s fur passing.