What breed is he?

This is my cat Cinnamon.

His mom was a barn cat my friend brought home whom she thought was a kitten because she was so small. It turned out she was pregnant. She was svelte and fully gray except a tiny spot of white on her belly. Her eyes were bright green.

The picture doesn't do them justice.
Both of them are very sweet and more than a little talkative. Cinnamon has a laid back personality but also very curious and intelligent. Everyone calls him siamese but I don't think that's the full story obviously.

How old is Cinnamon?  how blue are his eyes?

Momma, being slender and with these looks, may have much of a russian blue.  Daddy perhaps?   Even if grey RB look alike moggies arent unusual.

His eyes are very pale blue. And he is 7 years old.

The pointed gene runs in the general cat population. It's not unusual for farm cats to have 1 or 2 pointed kittens in a litter. It does mean there's some Siamese somewhere in their background, because the pointed gene only comes from the original Siamese cats. But there's no telling how far back that Siamese was. Could have been 100 years ago. So I suppose calling him a Siamese mix would be technically correct, but mostly domestic shorthair .

He's beautiful, and definitely Siamese descent.

Ok, so he has the siamese point gene, and his darkish becasue his masque is dark (sepia, or possibly mink) and he DID darkened up with age.

 I though, he has almost the looks of an burmanese point-mix.   A domestic whom is a burmanese point is rare, but  a mix of siamese and burmanese point isnt rare, as soon you had got your eyes open for them.  the easiest way to recognize them if a pointed kitten gets dark on body already as kitten, before being adult.  also, they eyes arent usually blue, or perhaps barely bluish.

But he is fully adult, and blue eyes, so he isnt such a mix - he is the "usual"  siamese point mix.