My boy Scooter is a case in point! He had 2 brothers and a sister in his litter. His mom was grey and orange with short hair. Scooter and one of his brothers and his sister were orange with short fur, and looked like triplets. Then there was the other brother. He was solid black, very long fur and quite stocky, while the rest of the family was thin. I think that there must have been another dad involved!
My other boy Clyde is the opposite. He was one of 12 kittens, and they were all black and white and very fluffy.