When designing your piece make sure you use CMYK color. Adobe’s InDesign, Illustrator and Photoshop allow you to set the color space in either CMYK or RGB. Microsoft Publisher also has a setting (though the default is RGB). Word processing programs are set to RGB and usually can’t be changed. So when printing from these types of programs remember the colors will shift.
Use CMYK on all printing needs, as the color will appear differently if printed in RGB.
RGB is what your computer screen uses. It is an additive type of color mode, that combines the primary colors, red, green and blue, in various degrees to created a variety of different colors. When the three colors are combined and displayed at their full extent the result is pure white. When all three colors are combined to the lowest degree, or value, the result is black. See the color swatch below, the inside color is white because it is all the colors added together.
CMYK stands for Cyan, Magenta, Yellow and Black. K standing for “key”. The black plate was typically called the “key” because it carried important key information relating to the artistic detail. CMYK colors are subtractive, which means that each additional color means more light is removed, or absorbed, to create colors. When the first three colors are added together, the result is not pure black, but rather a very dark brown. The K or black is used to completely remove light from the printed picture, which is why the eye perceives the color as black. See the color swatch below, the inside color is black. This is because the colors absorb the light.
Computer monitors give off colored light know as RGB (CMYK is colored ink.). Computer monitors have a larger color gamut than printing can achieve, which is why a computer can display a million more colors than what can be achieved with printing. You will notice that something looked different on screen than it does on paper and it is because of the different limited color ranges that computer monitors and printing allows.