Farah's Father?

Considering his coloration and history, I believe that Shahazar is Farah's father and Fiona's mate. We know that Farah must have a unicorn father and also leans closer to the pink/rose gold side. These two traits, as well as the few unicorns in the herd, help point to the original founder as her sire.

We also must look at the timeline. Since Shahazar chose Fiona as his successor, its very possible that they spent a lot of time together and had a romantic relationship.