More than any other aspect of tone, the thing that most people identify as a good tone have very little to do with bright/dark, reedy, etc. If the player has good, clean attach and release, good tonguing, fluid, natural vibrato, he will be perceived as having a "good tone".
Good intonation is also very important.
But ESPECIALLY important is how cleanly the note starts and stops. Let me tell a little story.
When I was in college many years ago, a good friend who was a Music Ed major, and trumpet player, continually got poor marks in her juries... everything else was OK, but they criticized her tone.
She was just about to quit, she was devastated. The brass teacher told her, "I think your basic tone is fine, it is your tonguing that is sloppy, and makes it all sound bad. This semester, we will work on nothing else, just tonguing." And that they did.
At the next jury, she got all A's. Some A-'s and some just A's, but they were all A's. All jurors made the notation, "Tone MUCH improved."
And all that changed was better tonguing.
So, there are many aspects to "tone".
Does that mean a bright tone is better, a dark tone is better? No... Paul Desmond's tone was perfectly suited to how he played with Dave Brubeck. And Cannonball had a huffin' and puffin' band, and his brighter tone was good with that, and blending with his brother Nat on cornet. Desmond's tone would not cut it in Cannonball's band.
And a very dark, classical tone, the kind the band directors want kids to have ("I want you to sound like a French Horn"), while blending well and disappearing into the tone of the symphonic band, is poor for projecting a solo in that same band.
So, these are some things to consider in deciding just what your tone should sound like.