There are at least two theories pertaining to color. One is called RGB (Red, Green, Blue) and is the premise used on the internet, and the other is CMYK (Cyan, Magenta, Yellow, Black) that is used in printing. It still boggles my mind that you can take either three or four colors, mix them all up, and come with a wide assortment of colors. The bizarre thing about these two theories is that they don't mix very well. If you create a document in CMYK and try to post on the web, the colors will be skewed. And if I create a piece of artwork in RGB with computerized special effects and transfer it for print, the special effects won't print and the colors will only be slightly off. Bizarre, isn't it?
And if you want to see if the RGB rods in your eye are the "perfect" size (i.e., you're not colorblind), here's a cool website: http://www.toledo-bend.com/colorblind/Ishihara.asp
May your mornings be blue with white clouds and your grass be green!