MOST casual horse owners ought not breed their horses, as we all well know. Most don't have the knowledge of blending genetics (which OP has shown) or the experience to train a young horse, or the finances to support and train multiple horses. Heck, even a lot of the professional breeders need sound spankings regarding what they are breeding. As the OPs horse is relatively young, I can't see that she's had a lot of time to prove herself athletically, and without stunning confOrmation, she hasn't "earned" the right to reproduce.
I am also wondering why the OP is so determined to have a registered stud, since the OP's mare is herself a grade mare. If one is registering to a color registry, it hardly matters if the stud is registered or not, or am I mistaken in that regard?
Sadly, since no one's opinions are going to change the OPs mind as to whether or not he/she should join the ranks of backyard breeders, the only thing I can add to the conversation is that color ought to be the last consideration in breeding. Pick a stud that excels where your mare falls short, and hope that the foal gets the best of both parents. I can't help but remember a Craigslist ad (think it was Craigslist) I once read in which the owner of a two or three-year-old was selling the colt because it came out the wrong color and she was so disappointed that she just didn't work with it. So the colt was left to its own devices and was barely halter-broke at the time of advertising. A throw-away, bred only for color.
And a lot of these people are the ones that protest the slaughter industry.