Very dark blue, almost black. Green eyes. I have seen pics on almost black russian blues. The problem is, he is not shouting: this is a russian blue...
Korats are a shade heavier, more bulky, but not Korat either...
That based on this one photo.
So, so far we must contend to call him for a Maltese Cat, ie a blue cat without any sure breed.
You are welcome to send some more good pics, and if you have any background info. For example, how old is Basil?
A 10 year old looks often differently from a 2 year in his prime...
I would say he is between 8 and 9 years old. I have had him for about 5 years and before I adopted him from a foster family that found him outside, he had been hit by a car (the photos of him half shaved are from that time period).
Tx for the extra photos! OK, on some of them his face looks almost as on some RB I know... And him not young, and perhaps with a somewhat "excellent appetite" taking from him the typical elegant, slender looks....
He may have began his days as a pet quality Russian Blue. But we cant come for sure any longer, even if we can say he is somewhat a look alike to a RB, so we must count him as a blue shorthair domestic, with the label of Maltese cat.
Yeah, I do see that little locket on his chest. Its only a minor detail adding to him doomed as at best a pet quality RB - such lockets DO occasionally happen on RB, but they are hereby immediately counted as pet quality, however nice their other looks are.