I don't actually use Buck as an eye shadow, but instead to fill in my rather sparse auburn brows. It's the perfect color if "brown" is just too brown for you. (I have the problem that anything too brown matches my freckles and makes me look ruddy.) This has an overall touch of rose in it that matches my hair well, stays all day and is totally matte. I got it in the UD Naked palette.
This is a colour that's easy to overlook compared to UD's extensive shadow range, but once you try it, you'll see how versatile this shade can be - the perfect matte brown that's not only pigmented, but works wonders as a brow or crease shade.