My kitty Radar Love is a weird little cat. He's two and the vet listed him as a blue siamese. I know he's not a pure breed, but I'd like a second opinion. He was born white and has light blue eyes.
He would be considered a Domestic Shorthair (DSH) unless you have proof of his ancestry. I don't see siamese in him. His head and body type aren't right for it and his fur is too fluffy. I would call his pattern van rather than pointed.
Pointed cats develop color on the cooler "points", usually ears, face, feet, and tail, but can also darken over their back and sides as they age. Weather makes a difference as well. They tend to get darker in winter and lighter in summer. The van pattern means a cat is mostly white with a few dark spots.
All siamese are pointed cats, but not all pointed cats are siamese. There are several other breeds that have the pointed pattern and they occur in the random cat population as well. I'm also looking at his pink paw pads. Pointed cats have paw pad colors that go with specific color points, none of them pink.
How old is he? Most kittens have blue eyes when they're very young and start changing color when they're a few months old. It's also possible that he'll keep the blue eyes. All pointed cats also have blue eyes, but not all blue-eyed cats are pointed.
It's hard to tell colors on different monitors, but I think your vet got the color right. Blue is genetically the dilute of black. (Don't ask me why it's not called grey :dk