The original idea was always to use gold leaf on the horns and other headdress decorations, contrasting with a pale desaturated skin tone. I had planned to have dark hair but that ended up changing when the highlighting spread too far and became a general colour change.
Overall I'm happy with the result. At some points I thought the gold leaf might totally overwhelm the piece and destroy any chance of focus but in the end it seems to work rather well.
I'd also like to thank Albert Moretó Font for suggesting I tone down some of the creases on the face. Really does make her look far more youthful.