Color Theory & Color Profiles

RGB & CMYK

This post is going to be similar to the previous post 'Pantones vs Process Colors' in the functionality of process colors (CMYK) for print. But instead of comparing Pantones and Process Colors, I'm going to get a little into color fundamentals as well as cover the different RGB & CMYK Color Profiles. You might have noticed at some point that when you print something out it looks different on paper than it does on your computer screen. This is because of the different media color profiles.

RGB (Red Green & Blue) are Additive Colors, meaning when a red light, a green light, and a blue light are added together it makes white light. This is strictly for digital (web). Kind of strange since we're used to red and blue making purple and green and red making brown, right? Well, the computer screen you are looking at right now is actually made up of tiny red, green, and blue lights. The white areas are where each of the lights are turned on, the black area is where they are turned off, and all the colors in between are the lights with varying ons, offs, and intensities. If you get out a magnifying glass or a loupe and look at your computer screen you can actually see the tiny rectangular lights.

CMYK (Cyan Magenta Yellow & Black) are Subtractive Colors, meaning when you take all the colors away you have your white paper. This is (if you recall) strictly for printing. When you add all the colors together you get black, when you take them away you get white (or the color of your paper), and all the colors in between are different combinations of CMYK. [Remember: There is no white ink. White is just the color of the paper that the image is printed on. If you are printing on ivory paper, all the white areas will appear ivory.]

The full color gamut for vision, RGB, Pantones, and CMYK.

There are a lot of different things to consider when it comes to color, because not all colors are/will be the same. All color is subjective. Our eyes technically see in RGB, and how we perceive color may be different than how your neighbor perceives color. Just like monitors: the color profile in your computer may be different than your neighbor’s, therefore the color that you see on your screen will be different than theirs. So it should be no surprise if something is a completely different shade of purple on your screen than on theirs.

An easy way to imagine how we see color is to imagine beams of light flying all around you... when the light hits an object, such as a leaf, all the colored light is soaked in but the green light bounces off, thus making the leaf appear green. Take a black car tire: the car tire soaks in all the color light and nothing bounces off, making the tire appear black. Remember, the absence of light is black (like a dark room).

We can see every visible color in the color gamut (with the exception of color blindness). The total amount of colors, i.e. all the colors possible within a given color space, is referred to as the gamut. RGB has the highest. We already know Pantone inks allow you access to colors CMYK cannot produce – as they are “outside” the CMYK gamut, whereas CMYK has the smallest gamut (the most limited range). Don’t let the RGB gamut and our visual RGB gamut confuse you: if you look at the image above, the ‘Visible Color Gamut’ is all the colors that we can see with our eyes, whereas the ‘RGB Color Gamut’ is all the colors that are visible on your computer, TV, or phone screen.

Color is also relative, especially in print. When printing on white paper, yellows will come out yellow and blues will come out blue. Whereas, if you try to print on colored paper, for example: brown paper, the color of your paper will show through your ink causing the color to change. Especially if it is a dark paper! This is a big issue with digital printers. Offset press is a little different, since the ink sits on top of the paper and is a little thicker than normal ink, the paper color can still affect the ink color, but not as much as with a digital printer.

Color is also affected by coated and uncoated papers. If you recall my example about the green light bouncing off the leaf making the leaf appear green, this is almost the same concept. Except this time, the difference between coated and uncoated paper is HOW the light bounces off. The same color can be printed on both coated and uncoated, but when the light hits the coated paper the light that bouncing off will all bounce in the same direction. Whereas the light bouncing off the uncoated paper will bounce in all different directions, giving the illusion of a different shade. But in actuality, it is the same color.

Glossy paper vs Matte paper

Because RGB is strictly for web and CMYK is strictly for print, there are a couple ways to set up your files with the correct color profiles. Otherwise, if you design in RGB and change it to CMYK, the colors will actually change from what they were originally. So to make sure that this doesn’t happen, it’s always a good idea to double check and make sure that your color profile is correct for the media you are designing for.

You might recall this if you read the ‘Image Resolution’ post, but in the New Document window it gives you the option to change your document profile. If you click the drop down you can choose to design for print, web, mobile and devices, and so on. Obviously if you select Print it will set up your profile for CMYK at 300dpi, and if you select web it will set your profile up for RGB at 72dpi. You also have the option to manually change your setting under Advanced at the bottom. The window will expand a little and it gives you the option to manually change your color mode, raster effects and preview mode.

In Photoshop’s New Document window, it is a little different. If you click on the drop down for Color Mode you can select which color mode you want to work in, and then you need to change your resolution for your image [72dpi for web and 300dpi for print]. Unlike Illustrator, though, you have to set up your color mode and resolution manually.

*Fun Fact: There are more shades of GREEN than any other color,
and YELLOW rooms actually make babies cry more than any other color.*