Types of tone
Pianos have certain types of tone, there is smooth tones, bright tones.
Sometimes hammers can age and compress, and the hammer can sound ‘harsh’. Other pianos come out of the factory with a smooth soft tone. Wool providers materials change, and so do the resulting hammers.
Voicing
It is more like your technician can make a harsh tone soft, through needling. Than make a soft tone brighter.
I have been called out to many a quality piano that perhaps sounded fine on the day of purchase, however after the years the hammers have hardened, and the tone is thinner than it should be.
Voicing is a factor that is worth discussing when buying a piano, as it may be the pianos voice can be altered.
What type of music will you play
If you are to play romantic music, perhaps a mellow tone will suffice. If you’d like to play stride piano, it may be a slightly brighter tone fits like a glove.
However, even with stride you want a rich tone. A piano with presence.
A better question
Instead of asking “does this piano sound bright, or dark?” might be to ask whether the piano sounds rich, vibrant and full.
A rich piano can be full sounding, and a bright piano can have a lot of vibrancy. The real question is whether the piano itself is exceptional. It is likely the piano will be owned for a generation or two. And it is rare to change a piano out once in the new home (moving costs etc.)
In summary
Choose the best sounding piano you can afford. With the most responsive action. It’s a combination of tone and touch. Print out a chart with the pianos you will try and try and rate each piano with such terms as ‘bright’, ‘mellow’, ‘rich’, ‘dry’.
We hope this information is helpful for you.