The Official Chapter Book series have said that "one of" (did not say which one) Applejack's parents was an Orange (pony-family surname); thus why her fur color is orange, and why she was lived with her Aunt & Uncle Orange in Manehatten for a time, during her Elements of Harmony origin-story from The Cutie Mark Chronicles (S01, Ep23).The Chapter Book also confirmed that both parents passed away (no specifics how) shortly after Apple Bloom's birth; this was also reinforced by Lauren Faust when asked about the subject, that she envisioned Applejack's parents having passed away. Whether they RetCon this, or spring the "faked their deaths" or "thought to be dead until now" scenario {which would be a cheap cop-out, in my opinion}, remains to be seen.Also, despite the fan-art and fan-fictions to the contrary, Applejack canonically holds no real acrimony towards non-apples products such as oranges &/or pears.