Tan skin is still closely linked to those who must work outdoors for a living (construction, farming, etc.). Those with education are able to stay indoors, thus preserving their skin.
You will see women carrying parasols on sunny days in order to avoid becoming tan.
There is recognition that some people are simply darker, but there's not an overall acceptance of dark skin being "normal."
My son, half Chinese-half caucasian, started kindergarten last year in a city in the northwest. My husband, is a naturally dark Chinese-American and my son inherited his dark skin. My son's nickname, given to him on the first day of school when no one knew him, was "Da Da Hei" . . . the equivalent of "Stupid Black Boy." He had the darkest skin in the class.
Here is an article about tanning salons in China. It also gives you the history on the value of light skin.
http://en.ce.cn/Life/entertainment/fashion&beauty/EFBft/200609/12/t20060912_8520848.shtml
Good luck!