I have not observed this phenomenon for myself because because do not recall every calling some such individual a "racist".

However, I suppose I see how such an occurrence may be a possibility.

It may be safe to assume that there are two types of people in this world; those who are racist, and those who see no need to demarcate personal beliefs along racial lines. "White" people are just alike everyone else in this respect.

However, it is of no use to deny that the countries where people are predominantly white, are usually more advanced in as a civilization in regards to the prevalence of education, social liberties, and cultural acceptance or diversity.

Of course this does not mean that all people of within this ethnicity share an affinity for these matters, or that they are all capable or willing to advance them. This means that the individual who white is not necessarily smarter than an individual of another race, it just means he or she has a much higher standard of education and more suitable social climate available to for personal growth. This point can quickly be understood if you consider the concept of the car, of the automobile vehicle. Even though it is driven by people of all social groups and ages, a very small minority has much of understanding of how they work or how to repair it, and even less of them would be able to construct a car if given the necessary materials.

In the same way, individuals of a caucasian ethnicity live in an environment which they themselves do not understand or comprehend, and which they could do very little to construct or replicate. The majority of people are usually dedicated to a job, single set of uniform tasks which do contribute to society, but these same people have a very little understanding of what exactly it is they are contributing, much less why or even how. This understanding applies to people of all races.

So then, countries in which the major (not even "native) demographic is white, usually have more technologically advanced living conditions. However, these are not because of race, but because of better, more strategic leadership by a very few select individuals.

It is undeniable fact that the world's biggest religion, Christianity, is beneficial for the growth and preservation of a peaceful society. The biggest compartment or sect within Christianity, which is Catholicism, has perpetuated many detrimental acts against humanity, some brutally horrendous. However, the atheist of materialistic person then has to admit that if there his own beliefs are correct, that the people who committed those acts were part of a group of people who would have found some other way or excuse to control and dominate other people and their believes since they were able to rationalize their delusions while neglecting the cardinal rule of their religion, which is the golden rule. From these events we can extrapolate two facts; that their are vicious individuals who will find a way to corrupt and inhibit progress within society, and that the the primary codes of conduct within Christian religions is primarily good in essence.

However, Christianity is originated in the middle east, conceived of by people who were not white, and was passed on along with other societal and scientific innovations within the region.

Religion is important and relevant to the answer which you seek, because it is an undeniable fact that most people in this world claim a religion, even if they do not follow it.

So then, the individual who is white lives in a world which seeks its peace from a religion from a non-white individual, and benifits from the inventions of individuals with whom he has very little in common with other than his or her skin color. Also, the origins of primarily white countries is usually rooted in forceful dominion and colonization, so a lot of the benefits of modern North American and Western-European countries were gained through violence, coercion, and the neglect of ethics and humanity. Also, it is unreasonable for any person to claim ethnic supremacy when their countries well-being depends on trade with a country of another racial demographic.

Tl;DR White people typically live in comfort due to conditions and advances which they do not contribute directly to or with a sincere intent. Therefore, they know at some level that they do not deserve to be called "better" than someone else. The racist might experience some form of guilt if he is called on his nonsense, and the non-racist be fearful of being perceived as racist and may become apologetic as a preventative measure.