Physical preference is not racism unless there is some other reason the person prefers, or does not like, people of a certain ethnicity or only will date members of their own ethnicity. I do think that someone who dates only based on physical preference is shallow. Also, like I said here I consider the reverse to be shallow.
I have a physical preference for women of my ethnicity, or of someone outside of my ethnicity with the same looks. Here is a fantastic woman who pretty much sums up my physical taste. She was a bit thin because of how she danced, she could not keep weight on, but other than that, she is an example of my physical ideal. This does not mean that I do not find women of all ethnicities attractive… I do. It is just my preference.
However, that is just physical preference. I am married to and hopelessly in love with a lovely German Lady, as white as white can be with a lovely smattering of freckles. We are at 6 years and going strong, by the way. If she had happened to be encased in the flesh of a black woman, a Latina, a Rromni (female Rromani Gypsy), or anything else when I met her I still would have married her. I am a very lucky guy that my wife decided to select me. :)
So, while my preference is someone of my ethnicity, that is not the end all for me. That is not what decides who I date and fall in love with.
Someone in here said that preference for specific ethnicity is more than just looks.
That could be or it could not be. Some are just interested in the looks, some have a fascination with the cultures associated with the ethnicity.
Also, some people are not comfortable with dating someone from any culture other than their own. I have heard that quite a bit. Even with them, if it is a matter of being comfortable with that culture without looking down on another ethnicity, I still do not call it racism. I think that the person is missing out on much, but do not call them racist unless they look down on other ethnicities. In this case, I do raise an eyebrow if they turn someone down who is of another ethnicity but has the same culture as the person.