This has probably happened to you: You select a photo on your computer monitor and decide to print it out, but when it comes out, the colors are not the same. Or you find a dress online and see a statement saying something like “Colors May Vary.” Why is that? It’s because monitors can be set to display color differently, and this is especially noticeable when you are printing.

It has to do with a concept called color profile. The color profile for a computer monitor, television or phone screen is RGB, which stands for red, green, blue. These three colors combine to create all of the colors you see on the screen. Red, green and blue are added over a black background and this affects the way the colors appear.

The ink colors used to print on paper are cyan, magenta, yellow and black, which are referred to in the printing trade as CMYK (the K stands for key or black). These colors are combined on a white background to create a full-color design. In a commercial printing press, these ink colors each have their own container. After the ink is applied to the substrate (the paper or other material that is being printed on), the ink roller is wiped with metal blades to remove any excess and keep the design clean and distinct.

It is possible to set your computer monitor to display CMYK colors rather than RGB, and most commercial printers will do this so that what you see on the monitor at the print shop is very similar to what will come off of the press. If you do a lot of printing at home, this might be worthwhile, but it could make your favorite shows look a little funny.

Just remember that color in one place is not always the same as color in another. Unless you need to reproduce colors exactly, it’s probably not worth tinkering with your monitor. A commercial printer can create just the right colors you need.