Photoshop 8 has few more working color modes than RGB and CMYK. ICC color settings can give you an outstanding control over color. You can set your Photoshop for any kind of work: Generaly CMYK color mode is used if your layout will be produced on CMYK based device such as a press printing ,digital printing , ink-jet printers and other devices. RGB color mode would be suitable if you are designing for a web, Photo Printer (aka Lambda) or slide presentation (digital or photographic). Following section shows multiple examples of many color cases and how your ICC Color Profiles should be set...