Still, if you don't have the more accurate word in your vocabulary, then don't use it. It will sound stilted and unnatural in the context of your sentence.
That being said, for anything that you want to be sure your readers understand, "write like you talk". http://www.paulgraham.com/talk.html
Most people's speech (excluding times where they have carefully written it in a manner different than unprepared speech) not only isn't colorful, it's unclear by words alone, though often helped by tonal, pacing, and, in person, nonverbal cues, and, in interactive contexts, interaction with active audience members, all of which are lost in text.
“Write like you talk” can be good advice for people who are dealing with a couple specific problems (either a form of analysis paralysis stopping them from getting anything written, or habitual overwriting) but otherwise it's just bad advice that ignores the radical differences in medium.