It's a cultural phenomenon. Stop using white American's perspective to measure everything in the world. The world is diverse. If the USA wants to lead the world, it must respect and understand other cultures.

Regarding the accident, there is no bad or evil intention behind the behavior. Just like "the N- word" is popular among blacks to show brotherhood bond; or "kudang yima" is the "F- word" in Tagalo (filipino language) but is used as "how are you brother!" among friends.

Dark skin has been associated with hard labor in the sun hence poverty; lighter skin, the opposite. Fat was associated with affluence, hence in ancient paintings, nobles are fat; just like in Africa, skinny is not beautiful. Even 20 years ago, being skinny was (and perhaps still is in some cases) considered ugly in China. This color preference does not apply to other races. It only applies to the Chinese. When Chinese look at africans or whites, it's not the skin color that matters. It is their wealth, behavior AND body features that is liked or disliked.

Th concept or the word of "skin color" in the USA has become a sensitive word because it is associated with the ugly things over the past 200 years or so. The images evoked in a mind of an American include slavery, white brutality toward the blacks, lynching, brutal black retaliation toward the whites, controversial Jewish roles on both sides, affirmative action, crimes, political correctness, unfair treatment of the whites, discrimination against the blacks by whites and vice versa, hatred between lighter skinned and darker skinned blacks, the awkward role of the mixed race, politicians' pampering to one race at the expense of the other,... just one word --- it is UGLY in the USA and its history till the present time.

China doesn't have this ugly historical baggage. Chinese do not really dislike or hate blacks. They just do not have enough interactions which leads to some ignorance. Once they are familiar with the blacks, they are most receptive towards the Africans. Just look how the Chinese government treats the Africans (sometimes better than treating Chinese), how many Africans are studying working and raising families in China, how many Chinese marrying Africans, ... you will know that "skin color preference" is ONLY APPLIED to CHINESE or maybe eastern Asians because it was associated with affluence or poverty. Even that, "black skin (heipi in Chinese)" is sometimes used as an affectionate nickname by friends or parents.

Of course, in a white American's perspective of American political correctness, everything changes. If the USA wants to lead the world, it has to try to understand other cultures. Otherwise, it will continuously have disasters in the its policies on Vietnam, Middle East, Ukraine, Africa, Asia, ......