Hard to say, really. I had an accidental litter from my Maine **** queen by the new seal point Siamese may years back. I got one totally black cat, one blue tabby, one black tabby and one brown tabby. I definitely knew the father, he was the only un-neutered male in the house and she opened a locked door to let him in...
Pointed cats are sensitive to temperature extremes. He may be darker in colder weather and almost ivory in hoter weather. My Siamese would get the most beautiful shade of ivory during the summer heat and his seal points would fade almost to tan.