CMYK and RGB?.. WDF?!
Have you ever created a design in Adobe Photoshop, saved it, and then uploaded it the web only to have your colors suddenly turn tasteless and not what you planned for? Well, so have a lot of buddies. Want to know what’s wrong? You’re not in the right color mode!
CMYK and RGB are the two most common color models you will be using.
I’m going to break them down this for you but don’t worry since in all major image editing software, you can choose which color mode you want.
You can also easily switch color modes if you realize you are in the wrong one.
RGB stands for Red, Green, Blue and it is considered a light additive color model. This means that colors are added together to produce lighter colors and eventually to produce white. RGB is specific to digital design – and if you are viewing anything with light behind it (your television, cell phone, computer, etc.) you are viewing RGB colors. If you are a designer creating graphics for web, you must be using RGB (or things will look really weird).
Something to be wary of – computer screens need to be calibrated (and pretty often, too) if you want to be able to ensure uniform color quality. This is especially important for photographers who want good skin tone in their pictures, and even for designers that are trying to match colors to already existing materials.
CMYK stands for Cyan, Magenta, Yellow, and Key (Black) and it is considered a subtractive color model. This means that ink is removed to achieve lighter colors. You will often hear CMYK referred to as “four-over” or “four color process”. This is because in printing you use all four colors layered over each other, as dots, to achieve different colors. This has to do with “DPI” or “Dots Per Inch” that you often hear about in printing.
With CMYK you can’t produce a color lighter than the surface you’re printing on – so when you are seeing white, it’s actually not ink at all – it’s the surface of your paper. In the same idea – lighter colors just have less ink, so that more white surface shows through.
Black, on the other hand, is more complex. First, it has two options. You might have heard a printer ask, or seen in your print dialogue box, if you want “plain” or “rich” black. Plain black is simple black ink, whereas adding colors together creates “rich” black. The actual CMYK values for rich black are C=75%, M=68%, Y=67%, and K=90%.
The thing is, even with those percentages, not all blacks are considered equal. If you are printing something for yourself or a client, consistency is key, so make sure you are not interchanging blacks, or using different CMYK values to get to black. This will definitely show up in printing! Though, knowing this, if you wanted a cooler back you could up the percentage of cyan, or conversely if you wanted a warmer black, up the percentage of yellow.
CMYK is actually a process that dates back to before our newer fancy printers. If you’ve ever worked with screen-printing or a printing press, you know the idea of layering colors. Well, CMYK is what was used in the beginning of printing to achieve different colors. Why do we call the black “K”? Because it actually stands for the Key plate, which was the most important of the four plates as everything was aligned to it.
How do I know when to use which one?
In short, if you’re going to be printing something, such as a business card, stationary, or a newsletter, use CMYK. CMYK does not include a white color because it is assumed that it will be printed on a white paper and depending on the percentage of each color that is used, the white from the paper will be used to fill the space, therefore making the shades appear lighter.
If it’s something that will only be seen digitally, use RGB. The Internet is set up to work exclusively with RGB colors and there is a simple explanation behind this. A digital monitor is made up of tiny units called pixels. These pixels are comprised of three light units, one for red, one for green, and one for blue. The RGB values are applied to pixels, thereby setting the luminosity for each of the light units in each pixel.
It should be known that there is no perfect correlation between the two types of colors, but when converted, a very close match can be achieved.
I hope that clears up any questions you might be having about the difference between the two color models. If you have any other questions feel free to ask in the comments, I’d love to help!