My natural hair color?

That's pretty much the colour I spend a fortune dying mine at the moment haha! I'd say it was dark auburn or chestnut brown. Very pretty colour either way.

I don't see auburn, just a light brown with a warm base. it's the same colour as my daughters

In hair colouring terms I would estimate that's about a level 4.5-5 golden brown. On my monitor I don't really see much red in there to class it auburn either.

This is why it is hard to classify colour online, to me it is nowhere near as dark as a level 4, more like a 6 on my screen

The lighting makes it impossible to tell the level of the hair properly. I one its underexposed due to the higher levels of lighting but the subject being in shade. In the other it's over exposed due to the reflections of light off the hair and the low levels of light in general making the camera force more light in to the shot. I'd say it's more of a mid brown that a light brown though, judging by the first photo and the parts that aren't heavily lit or in shade in the curls in the second photo.

I'd agree that there's not enough red for auburn, but chestnut seems about right to me.

I think this is a lesson in monitor resolution coz to me it has definite ginger in there, to me it looks exactly the colour mine is at the moment which is a Wella 5/4 which is to the chestnut side of a gingery mid brown!