Where your side hair starts to get a bit longer, up towards the top of your head, it looks denser than the hair below.
Whether this is just an illusion because of the length or even a reality, I think Yorkie's recommendation seems right because a 60% will replicate that.

Be sure to send in hair colour samples from the front AND the back of your head because it looks like it gets darker towards the back and the factory can replicate this too to get you the best colour match.