Blanket stitching over what you have done is not going to hide it, if you remove the (whip stitching) then blanket stitch it would be better. Finding a thread that matches the fabric would be better but if you want it to show/be decorative then a contrasting color works. When you want your stitches to not show its important to match those colors, your whip stitches would not be so (visual) if the thread matched. (And, the person who suggested zigzagging with a machine--that would show on the front-- )
Question.... Do you whip stitch your bindings? Visit a quilt shop, local guild or sewing group with a small practice piece (like a placemat- sandwiched, quilted and binding attached to one side) someone will be happy to take a few minutes to show you how to stitch an invisible stitch. :-)