color space and color sampling reference

I was having a hard time finding information about the differences between the color spaces used in Cinelerra. Then I actually looked up some entries in Wikipedia:

Color Space (general)
http://en.wikipedia.org/wiki/Color_space

RGB color space
http://en.wikipedia.org/wiki/RGB_color_space

YCbCr color space
http://en.wikipedia.org/wiki/YCbCr

YUV color space
http://en.wikipedia.org/wiki/YUV

Also, here is an excellent article on understanding color sampling:
http://www.dvxuser.com/articles/colorspace/

YUV-RGB Conversion Formula

Wow. I finally understand color sampling!
cheers.