Species doesn't matter much. What counts is the shade of the wood when dry. Make wood flour from various shades of wood and wet samples of each with water. That will give you a fair idea of what it will look like when mixed with epoxy.
A few very pale types of wood I tried didn't darken at all. Don't know why.

: I've got a couple of big gaps in the plywood joinery of the S&G kayak I'm
: building. I want to fill this in with a epoxy/wood four mix but am not
: sure what species of wood will be a good match. Grinding up okoume and
: mixing it with epoxy is too dark. I'm thinking maple or poplar. So, does
: anyone know a good match?