That looks like normal coloration to me. Chickens can have several different colors of skin on their earlobes: white, red, purple, and combinations of colors (like your hen).
Interestingly, we had this discussion on the Aussie thread a couple of weeks back. It started with a couple of people mentioning that the “colour of the earlobes has drained away”. Some responses were: “Silkies ear lobes can go white or fade with age”. “Dry skin in summer and fungal skin conditions such as Favus can also turn lobes white”. The responses in general were that it was nothing to worry about unless it was “crusty”.
