Adobe CS5 Illustrator Color Mode
You can change your preferred color mode in Adobe Creative Suite 5 (Adobe CS5) Illustrator. This allows you to create for print or web with the best color model. Every time you create a new file, you choose a profile. This profile determines, among other things, in which color mode to create your document.
Typically, anything related to Web, mobile, or video is in RGB mode, and the print profile is in CMYK. You can also simply choose Basic CMYK or Basic RGB. Here are the differences between the color modes:
Basic CMYK (Cyan, Magenta, Yellow, and Black): Use this mode if you’re taking your illustration to a professional printer and the files will be separated into cyan, magenta, yellow, and black plates for printing.
Basic RGB (Red, Green, Blue): Use this mode if your final destination is the web, a mobile device, a video player, a color copier or desktop printer, or a screen presentation.
The decision you make affects the premade swatches, brushes, and styles and a slew of other choices in Adobe Illustrator.
You can change the color mode at any time without losing information by choosing File→Document Color Mode.