Most color printers today (including your desktop inkjet) print in CMYK (Cyan-Magenta-Yellow-Black), also known as “four color process”. All colors in your printed piece are produced from these four colors. However, all computer monitors display color as RGB (Red-Green-Blue).
If you create your file in the RGB color space, the color will look different when printed on a CMYK printer, so it is always a good idea to create your artwork in the CMYK color space. If color is very important to you, we recommend you request a free press proof.