Mike - Prior posts from other builders claim that wood flour mixed with wood glue still is somewhat yellow when dried and is typically not preferred for the most part.

I didn't have too much filling required but when I did I used wood flour (slightly lighter in color than the surronding area) to fill voids, mixed with epoxy (which will darken when mixed) for most of it. If you noticed the picture of my deck I used white pine and I used wood glue by it's self to fill, which turned yellow, which matched the pine very well. Better than pine wood flour with epoxy which would of been darker.

Hope that clarifies!

DAVE