Sandfire is more of a brand name rather than a specific colour name. For instance, Sandfire Dragon Ranch produces reds, oranges, yellows, citrus, hypos, etc, and all are called "Sandfire." It's like the difference between a tissue and a Kleenex. One is a generic and the other is a brand name - all Kleenex are tissues, but not all tissues are Kleenex. So basically the only way to know if your dragon is a Sandfire is if you know that he or his parents/bloodline came from Sandfire Dragon Ranch.