Some of my furniture (not stereo related)is made of solid cherry with no veneer. I have had them over 3 years. Cherry does darken over time and should reach 70-80% of it's final color within 6-8 months depending on air, sunlight, etc. Afterwards it darkens more slowly and will reach it's final color within 2 years. That's what the manufacturer told me and that's been my experience. So, no cherry does not darken forever, and it does darken faster in the beginning. Just remember my experience is not with veneer. I also want to add one thing. Being that my furniture includes end tables, where various knick-knacks covered parts of the pieces. Sometimes I didn't move things around for weeks and never found "tan lines." Therefore as BMPNYC pointed out maybe they were there to begin with. It would seem that one week with no sunlight would not be enough time to cause "tan lines." I don't know if this info helps or adds more to you dilema. Anyway, good luck.
NATURAL CHERRY VENEER
I left my new Nautilus 805's sitting in the bottom piece of the foam packing they were shipped in, and placed them on top of their boxes (free stands) while I went out of town for a week. When I came back, I took the speakers out of the foam bottoms and noticed a "tan line" where the speakers had been sitting down in the foam packing pieces. Here's the question, Does anyone know for sure, whether natural cherry continues to darken with time, forever, or if it reaches a certain point and then stops darkening alltogether, or slows dramatically??? My curtains were drawn, and very little light was able to enter the room. I believe that they will even out with time, but the Obsessive-Compulsive in me has decided to cover up the "tan" part and let the non tanned part acquire some sun. So.... Bring on the info!!!! Thanks.