China and its Confusing Colors

During a discussion with some Chinese friends today we began to talk about computers, the internet and its effect on China.  During the course of this conversation I learned something new about Chinese colors I had never heard in my two and a half years here.  It went something like this:

"So Gary, what are your thoughts?"

"I think the internet is both good and bad.  It is good because I love to play computer games (a common pasttime here) but I think it is also bad because of all the yellow pictures" he said.

"Yellow pictures?"  I had an idea what he meant, but I wanted to make sure.

"Yea.  You know, yellow pictures and yellow movies" he replied while making some hand motions and beginning to blush.  It was now obvious he was referring to indecent pictures and inappropriate videos that even here in China are an epidemic despite efforts by internet censors.

"Oh, I see." I said, trying to ease his embarrassment.  "Yes, I agree with you that this is not a very good part of the internet."

It was interesting to learn this new meaning for yellow, but it doesn't quite make sense to me.  What about the Yellow River in China?  Or the Yellow Emperor, the legendary first emperer of China?  Seems that somehow this color, which at one time was used to describe people of Asian descent (even the surname "Huang" - meaning yellow - is a very common name), is now used to describe something inappropriate or offensive.  It's not a color association that we would make in America.

This isn't the first color difference I've run into since being here.  It seems that red, for example, is the primary wedding color for a bride's dress.  White, on the contrary, is many times used for mourning (although most Chinese brides still have a white dress as well).  It's backwards and confusing, but living in China and especially here in Xinjiang, we generally expect as much.

It's made me wonder, though...are there any other color associations not mentioned that are prevalent here in China?   In English we tell someone that they "look blue" today or that they are "red with embarrassment".  What other confusing Chinese color associations are there?  I'd love to know.