If you want a REALLY nice colorful thoroughbred, consider Goldmaker: Goldmaker - Avalon Equine
However, I am not sure what he has produced from mares like yours. You may want to ask Kathy. She is wonderful to deal with!!
Also, I have PERSONALLY seen and worked with SEVERAL Guaranteed Gold offspring, and the one thing I can definitely say is that he is consistent with reproducing certain traits. From what I have seen he definitely produces a nice hindquarter, and usually he improves a neck and head. Are you looking to produce a colorful, amateur-friendly horse that is trainable? You might like a GG foal. His owner may not be everyone's cup of tea, but to call her "crazy" on a public forum is a bit overboard, no? It's just in poor taste, whatever your personal opinion. I think that we should ALL manage to provide an opinion without resorting to name-calling. Just my $.02.
Off my soap box now. In all honesty, if you are going to look at thoroughbred stallions, you really want to consider one for the quality of their offspring, regardless of color, and consider ONLY those that are actually producing offspring that are having success doing what YOU want to do, out of mares similar in type and breeding to your own. They do exist, but maybe not so much in a colored package. Color should be the last consideration, especially with a maiden mare of somewhat "spotty" lineage. She looks like a nice mare, but you really don't know what might come through in her offspring, so you want to be VERY careful to find a stallion that really stamps his offspring with the type you want.
I really don't think there is much better than a GOOD thoroughbred stallion. I use nice thoroughbred stallions liberally in my breeding program, and I have about 5 on my short list of "must use someday". On the other hand, I could say the same thing about a GOOD arabian stallion.
For your mare, I would stick to a good arabian...but finding one producing offspring consistently out of mares similar to yours may be difficult. Not that they aren't out there, but I imagine they aren't as glamorously advertised as some of the more popular, pretty boys.