A few posts ago you stated "You can't always determine a person's race by looking at them." And now you are saying that to determine race you must either look at someone and then make an assumption or just take someones word for it and use whatever they feel like calling themselves on any particular day. So anyone can be any race at any given time simply because they can choose to call themselves whatever race they want? Is that right? If thats the case, how can you offer any kind of protection or even define what a "protected class" is if anyone can bullshit whatever race they want to be?
It doesn`t make sense to give special protection to something you can`t define.
No, you cannot always determine a person's race by looking at them.
Yes, I personally make an assumption about a person's race when I look at them.
Yes, I take someone's "word" for it when they choose to tell me whatever their race is (which I never ask anyway).
No, race doesn't matter to me, unless I'm making an employment decision, in which case I ensure my decisions are race neutral.
And . . . unsolicited . . . no, I will not keep repeatedly answering the same dumb question.

If you want to know how some place like the Equal Employer Opportunity Commission handles race discrimination, use Google.