Do you really believe this is always true? I'm not so sure. I believe that people in different areas of the world have different preferences in skin tone, but I don't believe that a lighter color is always preferable. Many people spend much of their summers trying to darken themselves with the perfect sun tan; they certainly prefer a darker tone than their natural coloring. I imagine there are certain countries (in Africa or Asia, perhaps) where the darker the skin color the better; it may also be true that Scandinavians prefer a much lighter tone because of their year-round lack of sun. I imagine in the long run the depth of a person's skin color is merely a matter of individual tastes.
In my opinion, this is connected to the way that power and wealth has been distributed in the world over the last few centuries. In general, the people of the world who have the lighter skins have been richer and more powerful than those who have darker skins. This has been happening since at least 1500, I would say.
If you think about the last 500 years, you will see that the Europeans and Americans (who came from Europe anyway) have dominated the world. In my opinion, people like to copy those who are successful and they think that the attributes of successful people are better than those of less successful people. That is why many people prefer light skinned people to dark skinned people.
I am dark-skinned. We know that skin color is not correlated to human intelligence and hence money and power will also be not correlated to skin color. However, I believe, light skin (white color) reflects more light and is eye-catching as compared with dark color which is more hidden and mysterious.
Any child when offered a white and a black ball should naturally select white ball as its more visual, light-reflecting and apparent. The child is able to see it more and will move towards it.
Any other theories I read on the web about wealth distribution or white rule over Asian and African subcontinents are fallacious.
Woman's attraction to dark color might be due to dark color's association with strength unlike white color which is more sensitive. I am not sure about this paragraph.
However, the color attractiveness is in the nature, I believe and has nothing to do we power/ rule of whites over blacks in the last few centuries.
In the true sense the question is not tenable .For skin-color matters little for the choice of a friend or man in general .The quality of a man and his virtue attract us .A race is liked by the other races in proportionate to its achievements and contributions .At present America is a mixed-skinned nation , but it enjoys the highest popularity in the world .The Mongols of the middle ages were the most powerful trace , and they were light-skinned people .But who like their barbaric activities ?
I think that we should attach precedence over humane-qualities , than the akin of a man .
Basically, it comes down to these facts...
1. The world has been dominated by European people for the last few centuries
2. Money, power and success are very important social markers and humans make very quick conclusions about peoples' wealth and status based on their appearance.
3. Everyone wants to be associated with success and wealth.
So, for the last 300 years, Europe and her descendants have completely dominated the world. Europe's values, preferences and fashions have been unopposable. For 3 centuries, success has been associated with white skin.
Also, rich, wealthy succesful people work indoors and stay pale. Poor people work in the fields and their skin darkens during their labour. In Europe 100+ years ago, rich women avoided getting a suntan at all costs because it was associated with the peasantry. In India today, this simplistic division of social roles still exists (see link below) and dark skinned people spend a lot of money to bleach their skin.
In essence, everybody wants to be on the winning team, and, generally speaking, dark-skinned people have not experienced dominant power for the last few centuries. With the new rise of China as a super power, perhaps the 'image' of success is about to change.