Originally Posted by rrich
Just leave a piece of each in the sun light for a day or two. Cover half of each with something like aluminum foil. In a day you'll start to see the diference. That will give you an idea of the change that you can expect.
BTW - I think that the poly contains UV inhibitors and may slow the natural aging effect. I would use something like Minwax Antique Oil Finish.
I think only SPAR poly has UV protection, not regular poly
That's true. Finishes intended for interior use don't usually have UV inhibitors. The Minwax Antique Oil is just an elaborate wax type product. It offers not more than a visual enhancement that would need repeated applications over time. It would do little if anything to aid or slow the aging process. The question in the OP seemed to ask if the veneer and the solid wood will appear similar, or age equally over time.
There are many conditions affecting the look and color of wood used indoors. In the same casement, there could be veneer and solid wood. For trim, there could be periods of natural light from outdoors, with long or short periods of sunlight. There could be areas where the only exposure to light would be artificial light, from incandescent, halogen, or flourescent lighting.
Two different selections of veneer (different flitches), and random solid wood selections for trim, each may take a different look. There is no control to keep one wood surface uniform to another in the same proximity.
IMO, the beauty of wood is the overall look. Trying to keep a piece of furniture with a combination of veneers and solids uniform in color seems to me to defeat the reason to use real wood and real veneer. Differences in grain and colors is the natural beauty of the material.
If the look wanted is a uniform grain and color, there are composites available with vinyl covering, Formica finishes, and photo finishes, that look like wood.