RGB, CMYK, and spot - Illustrator Tutorial

- Let's talk about the three systems of color most designers deal with, RGB, CMYK and spot. We're going to start with RGB. RGB colors are used on screen. RGB stands for the Red, Green and Blue colors of light that create all the different hues that you see on your monitor. Here's an RGB blue with the red value of 51, it's got a green value of 102, and a blue value of 255. Each of these RGB values can go from zero, which means a color isn't showing up at all, all the way to 255, which means that the color is at full strength. So, RGB colors are light based, and they're for on-screen use. CMYK colors on the other hand, these are for print media, and especially for a kind of printing called process color printing. It's a kind of printing that uses all four of these colors. CMYK stands for Cyan, and that's a kind of blue, and Magenta, Yellow and Black. And yes, the K, it actually stands for black because it refers to the key plate in traditional printing. And why these four colors? Well, it's because with them, you can come up with all of the many many many colors that you see in print media. And this happens when various percentages of some or all of these transparent inks are either printed alone, or on top of each other. And they can go from solid or 100% all the way down to 0%. And all these lighter shades of CMYK colors, they're made by printing as half-tone percentages, or screen tints. And these are different densities of tiny dots that are usually too small to be seen without magnification. And here's a closeup of an illustration that's been printed with a muted blue, and the blue is made from different half-tone percentages of all four CMYK colors. And above the design, you'll see how CMYK colors are notated. It says 75c, and that means 75% cyan, and 55m or 55% magenta, 43y, which is 43% yellow, and 20k, that's 20% black. And here's a closeup from a color photo. You can see how it's the mind boggling array of tiny half-tone dots of various sizes from each color of ink that create this image that we see with our eyes. And last, let's talk about spot colors. A spot color is a pre-mixed color of ink. If you want to just print your business cards using say, purple, you can print them using a single-color printing press loaded with just the purple spot color. This, as opposed to printing it using a blend of all four colors needed for process-color printing. Designers can select spot colors from the swatch menus of programs like Illustrator, Photoshop, and InDesign, or from printed catalogs and swatch books offered by companies like Pantone. And most designers do choose their client's official corporate color, or their colors using spot colors and this is a really good idea because spot colors are far more dependable for accuracy than CMYK colors. Also, when a client specifies a spot color for vendors involved in different kinds of media like printing, packaging, vehicle graphics, and sign making, they can pretty well count on the color looking the same. Okay and there are connections between RGB, CMYK and spot colors. For instance, after you choose a Pantone spot color, programs like Photoshop and Illustrator can convert that spot color into a four part CMYK formula. These programs, they can also do their best to translate both spot and CMYK colors to RGB formulas as well. And that way they'll show up pretty much the way they're supposed to on your monitor. Translating colors between different color systems and different output devices, your printers and such, it's an imperfect science at best, and until things get really resolved in this department, you can at least improve your chances of color accuracy by doing these two things. Calibrating your monitor so it displays color as accurately as possible, and asking your print vendor for suggestions and tips every time you're preparing a document for color printing.