Look up zillionaire he produce buckskin or pallys to a chestnut mare. His sf without a guarentee was $1500 I think . 2500 guarenteed. And look at http://www.blazingcoloursfarm.com/ her studs , I think more than one also produces what you are looking for.
Sometimes it nothing more then an advertising ploy. I did it for a few years to get certain mares into my stallion. Even though it was all up to the mares for those colors. It is just a way to get some good mares in. I had several restrictions on the deal not just more money.