I am curious about what palette to use for what purpose. I know you are supposed to use CMYK palette when designing for separations printing processes, but on the other hand - you could use the RGB palette just as well, if you have a color calibrated system and a printer profile and if you leave a PDF to the printer, which I suppose most people do. It works if you set the color output to CMYK and use the printer ICC profile for conversion.
So, what is your choice regarding color models? It would be interesting to hear how you all work.
RGB is a additive, projected light color system. All colors begin with black "darkness", to which different color "lights" are added to produce visible colors. RGB "maxes" at white, which is the equivalent of having all "lights" on at full brightness (red, green, blue).CMYK is a subtractive, reflected light color system. All colors start with white "paper", to which different color "inks" are added to absorb (subtract) light that is reflected. In theory, CMY are all you need to create black (applying all 3 colors at 100%). Alas, that usually results in a muddy, brownish black, so the addition of K (black) is added to the printing process. It also makes it easier to print black text (since you don't have to register 3 separate colors).Most screens (computer, phone, media player, television, ect) are RGB (e-ink screens being an exception), the pixels have little subpixels that just show red, green or blue.Most printers print in CMYK color (though some photo printers will print with expanded colors beyond those 4).So if you're ever doing something for a screen, use RGB, if you doing something for print, use CMYK.
Wow! this post is 12 years old! And the discussion continues...
Of course RGB has a wide range of colors, then it allows brighten tones that are not available on CMYK. But if you will print on CMYK (as most printing companies) you should use CMYK in order to obtain the best result, as close as possible.
Anyway, some printers allows more than this. For example, some plotters use 6 inks (CMYK+2 extra inks) or 8 inks, that allows to print more colors, specially bright tones (although it's not the same than RGB). On this situation, you can send an RGB file in order to obtain a better printed image. But it's not the same rule if you will print as CMYK, because the RIP should convert RGB to CMYK, according the color profile and settings choosed on the RIP. So, you don't have control with the convert process or results.