So this is the original version of Callista in the beginning stages of my creating her character!
Some of the first readers might have seen the second one in the Character Reveal Chapter (before I replaced it with the newer version of Callista).
I kept the skin color and eye color the same in the new design of Calli and then added it where she had half brown half blonde hair. Due to the genetic modifications she underwent, it made her hair become two colors.
Fun fact: Jango Fett's sister, Arla Fett, had blonde hair so I think that's how Omega has blonde hair - it's in the genetics. And why Callista has half blonde hair also.