He's brown tabby with white. I don't know if the tabby part is spotted or broken mackerel--that can be hard to tell for sure. The way his white markings go in a stripe down his side and back is really cool! Any other pics of him?
I'd call this color/ pattern Brown Spotted Tabby and White. but as Willowy said, it can be hard to tell between mackerel that's just a bit broken up, and where the pattern is so broken up it's called spotted. but from the first photo I would say spotted.
and I would call it very unusual to have the white going down the spine like that. White markings are caused by a White Spotting Gene , but exactly where the white and where the pigmented part will be is determined during development of the embryo. and normally the pigmented part starts from the spine and goes down from there. the white is more normally mostly on the underside of the cat. Sure there are cats with a white patch on their upper side or back . but a big white streak down the spine? Something very unusual happened there that the color got skipped ! Then it looks so cool with it going to what appears to be a band around his middle! That is just WILD !
Ah, I see he is different on the other side . Looks more of a 'harlequin pattern' from that side. And I am sticking with Brown Spotted Tabby and White.