I identify as white simply because I recognize I have privileges other races don't have as often.
You could be more specific and say I'm by coincidence a very large part Sami, but I'm not part of the culture, all my fully Sami relatives are really far back in the family tree and I've never known them, and people who look at me aren't going to see anything more than a white person, and thus I'm afforded the privileges of being white, so therefore, why call myself anything other than white?