Okie is the overo.
Then they both are.... Post a picture of him where you can see his color. SL doesn't have any white that crosses her spine does she? There's lots of other little complicated definitions, but that is the key.
Overos do not have white splotches that cross the spine, Tobianos do, and Toveros are a combination of both ideas, where they are solid, but white, over the spine from head to tail.