Changes in brightness over the first year

[pianorama]

Is it reasonable to expect new pianos to brighten up over the first 6-12 months of use? I have heard and heard of this happening before, but I'm wondering how consistent this phenomenon is.

I'm buying an Essex EGP-173C which overall I'm happy with, although at the moment the treble is on the bright side. My technician will be voicing it down for me, but I'm curious if I should plan on this being a constant battle for a bit of time.