I'd emphasize the fact that the horse you are selling is gaited, not so much the color/pattern of your horse.
As the saying goes, a good horse is never a bad color. And putting too much emphasis on the coat color in an ad will likely draw the attention of people who are shopping for "color" but expecting to buy a stock horse or other non-gaited breed.
Post pictures of your horse along with the ad - that by itself should be pretty self explanatory about what her coloring is. Make sure you mention what her registered breed is, if she can be registered as anything else, what kind of work she has done up to this point, etc.
It shouldn't be hard to find other gaited horse people in that area - it's just a matter of knowing what they're likely "searching" for in posted ads.
"Parelli horsemanship is just like painting by the numbers. You need absolutely no skill. You just put this color here and this color there, and when you're done, you have ... a mess no one wants." mp