A large number of advertisements posted were back in the sixties or before. That was a time when not just racism, but a lot of derogatory material was in advertising. There was sexism, xenophobia and a lot of things that would really be abrasive to our modern sensibilities. It was not just in advertising, you could see it in film, books, comics, and other media and everyday life. Many comics like TinTin and Asterix receive criticism for their xenophobic portrayals and even beloved children's author Enid Blyton received flak for how she etched some characters.
The issue here is cannot be narrowed to 'racism' but sociocultural perceptions prevalent in a generation. In the frame of time many of these ads were reflections of how society perceived things. While some maybe blatantly racist, even progressive elements in society perceived women, African Americans, other ethnicities in certain ways and they exaggerated these perceptions - not always in offense but in humor or to make a point. At best it was very uninformed insensitivity, but not always malicious.
Mark Twain was not a racist. In fact he was a progressive of his time who was against slavery as well as segregation. However, his characterization of Jim in Adventures of Huckleberry Finn is unpalatable to us today. Jim is described very stereotypically, there is blatant use of words like nigger to describe African Americans. If any modern day author created Jim, he would be deemed a racist. However, it would be incorrect to label Mark Twain as such without understanding the frame of his times.
Similarly Enid Blyton always portrayed men as in charge, women as meek, obedient and submissive. In her books boys sought adventure and roughed it, girls were proper played with dolls and had tea parties. Even her tomboy characters like George and Darrell were often negatively characterized for their masculinity and would eventually come to terms with their femininity. To the modern reader such rigid male female gender role portrayal and intentionally making women obedient and submissive to men would be offensive and feminist would be up in arms against Blyton. However, the truth of the matter is Enid Blyton in her frame of time was a feminist and her characters George, Darrell as well as the entire series of Mallory Towers, St. Claire strongly express her thoughts on more freedom and liberty for girls of her era.
Lets come to modern times. There definitely is a trend of dark or dusky people being marketed fairness products or being airbrushed to appear fairer. However, thats not the only trend. Men and women are expected to conform to certain physical standards. Men are airbrushed to appear more buff, ripped etc while women are airbrushed to appear slimmer, bustier etc.
To lump it all as racism, sexism etc would be making quite an unfair leap. These are all serious issues where one group believes it is superior and acts in a manner showing the other group as inferior. There is a sense of derogation and hostility.
I don't feel this is the case here. We all have our preferences on whom we are attracted to. Not all women are into buff athletic men, many like the scrawny ones, some even like bigger men. Not all men are into slim, perfect figure women, many like women who are bigger. People will find certain ethnic groups, nationalities extremely attractive over their mannerisms, appearance, accents while find some others as a total turn off. People who may find themselves unattracted to dark people, short people or Japanese are not exactly racist or xenophobic, they just happen to have their own sexual preference. We don't accuse straight men or women as sexist for completely ignoring the other gender do we. Physical attraction is just another layer like emotional or intellectual attraction. I mean we never make as big a hullabaloo if people like or dislike shy sweet types, or find accountants dull, or businesspeople to arrogant. Its all personal likes and dislikes.
What we really have is changing sociocultural norms and preferences. The problem we have is that a sociocultural image is being assumed as a "norm" as "desirable" as "mandatory" rather than just a "preference". The advertiser on their part is merely portraying what they deem as a majority preference - that is lighter, clearer skin is better. Of course they need to realize their influence and be more judicious in their portrayal. At the same time people are allowing themselves to be more easily led by ads.
We behave like kids when a cool new toy is shown on television, we must have it and every kid who does not have the toy is cool. The advertisement is merely showing a certain skin tone as "cool" but the fact is everyone does not have to have that skin tone, nor is anyone without that skin tone "uncool". It is a vicious cycle of advertising and impressionable society. Thats why I feel its more of sociocultural perceptions and behavior rather than something malicious like racism.
In similar vein the Volkswagen suicide bomber ad or the Spanish team being Chinese can be taken in poor light. However, I'd give them benefit of the doubt rather than dub them malicious, stereotypers or racists. Its just in jest or humor. If I take a picture with Asian eyes - am I making a statement against Asians or making fun of them - or is it just me trying out Asian eyes - its a matter of perception and a fine line. I've noticed that in USA integrated minorities don't take is as negatively, but segregated minorities do. Part of the issue is reaching out beyond your community and learning how actually your community is perceived rather than assuming that they think negatively of your community.