I recently bought a pair of Strands and 5th Avenues both in walnut, that show similar uneven finish. This is because the lt. brown staining of the walnut is not as opaque as say black or dk. brown. More like as in staining wood. It will even out and fill in after a few polish and wax treatments.
What I do is first polish with the AE walnut polish, as it has a higher stain and pigmet content than wax, then brush and buff. Allow is to set and cure for a half day, then a coat of Kiwi, to give them more shine. I might add, that I use a pallet knife and pc. of hard plastic to custom mix some Kiwi tan and a pinch of brown, to a matching color to walnut.