All you have to do is read a few different sims or a writing challenge entries from members of the Starbase 118 Fleet to see that each and every officer and member has their own style. That style can manifest in a variety of ways, but perhaps the most pertinent, and the one we see most often, is something we know as the tone of their writing. From dark, to comical, each writer here sees a scene from a perspective all their own. Using that perspective, they strive to convey things from the point of view of their own character. And over time, we come to know, and love (or hate) that persona.
Without the tone that inevitably conveys a steady character, regardless of whether the character themselves is actually steady or not, characters never quite become real. It takes time to develop your tone too, which can be frustrating at times. Thankfully, there are plenty of writers out there who are willing to share their experience and knowledge. Take, for example, this article on Tone. Not only does it explain more about what it means when someone talks about this seemingly ambiguous term, but it also offers some help on developing your own.
Why is it important? One of the pinnacles of every character is the moment where the being we created on a piece of paper steps from the shadows to become something more than a two dimensional thing. Developing your style, and your very own tone, is perhaps one of the most important steps towards the goal of truly bringing your character to life. So take a moment and read, learn, and grow, using your own voice to nurture your characters until they too step off the page and into memories.