You've just reminded me to have a go at mine later today NanKate. I'll pluck out any very obvious stray hairs, usually not that many, then dye them a mid brown. They have turned quite white (though my hair hasn't)
It only takes a few minutes and it's amazing what a difference that makes.
I might give my old dog a bath and trim too though he, like bags doesn't care what he looks or smells like. I don't mean bags doesn't care what she smells like, I'm sure she does - cares, not smells - getting myself in a tangle here better leave it at that.