There is only 1 Race & that is the Human Race!

If your racist & prejudice of other ethnic cultures as a provider you should state this on your website, so no one waste their precious time.   I do not discriminate, and appreciate disabled gents as well.  African, American, Hispanic, Asian, or Pale Ale it does not matter as long as your a respectful man.

It's racist, and I think less of the woman in question (and yes, I have seen some black providers set that prohibition on black clients - don't know what that says).  That said, I usually only see it in Backpage ads with no other screening indicated, so it may not be intentionally racist but rather a quick-and-dirty proxy for social status (some providers screen by age for similar reasons, but that lacks the nasty baggage.) Requiring references should be sufficient to screen out guys who will treat a provider badly, whatever race they may be.

but probably some racial stereotyping.  Some gals want to avoid prospective pimps from what I have been told.

Do you limit the races of providers that you based on personal preference?

I just care that they choose me

For me, I prefer dealing with Asians, and it's obvious why I feel that way. I don't discriminate per se, but I can tell you most of my best experiences have been with the Asian culture, which leads me to give them top priority when booking.

I judge a man not by the color of his skin, but by the content of his envelope.

so there are no surprises. Besides, I don’t take offense if someone says no but has never happened to me. All I am saying, it doesn’t matter because I am not here to change how someone feels about race and ethnicity.  

Of course it is a matter of personal preference.  

One advantage I have is that my screening is always easy. I am neither white or black.

I've hobbied in a lot of parts of the US and in a couple of foreign countries.  I've had a handful of ladies decline to see me because of my ethnicity.  The other 99% were fine with me just as I am.  To the other 1% I say it's a free world and given the uniquely personal choice that a woman is making when she is intimate with someone I believe she can employ any and all criteria she wishes. Her body her rules. If those rules exclude me I can quietly move on.