I don't think she's greying. We had a Pali exactly that shade, and he had a lot of "grey" on his face when he was in his summer coat. It was just his dark skin showing through the shorter cream hairs. He was 12, so there was NO chance of him greying out, although an insane number of people thought he was grey in the winter because he went white. He was definitely palomino because on darkening feeds, in summer, he went apricot with copious sooty marks.
We currently have a buckskin that for the past year or so has been roughly that shade of cream, just with the black points that make her bucky and not pali. She's also got the same "greyish" areas on her face, in her summer coat, but can't be greying because her sire was buckskin and her dam was black. I honestly think it's just the dark skin showing through.
A CLEAN SLATE FOR THE FUTURE