Consider bleaching with oxalic acid, inlaying a piece of birch and using the woodburning around the edges to hide them, a whitewash of lightly tinted stain, or paint the area and then sand back through the paint to reveal the wood grain in most of the areas.

The more diluted your paint or stain the more the original wood will show through. Don't be afraid to cut it with LOTS of solvent. White paints particularly are generally loaded with pigment so they have "covering power" or opacity. 20 parts of solvent to 1 part of paint may still have too much pigment and too much covering power. A few drop of paint well mixed into an ounce of solvent may seem to be too weak, but you can apply several coats to build up the effect gradually.

Another option is to give it an air-brush effect. I do this with an aerosol paint can held 4 to 6 feet above the well masked area. A light mistingin the general direction of my target, and the finely dispersed paint droplets are nearly dry when they hit. Sometimes the effect is so slight that you don;t notice it until you pull up the masking tape and see the original wood next to it.

Hope this helps

PGJ