What are RGB and CMYK?

Designers, photographers, and all tech nerds alike talk about RGB or CMYK colors all the time; and the average person usually has no idea what these mean! With good reason, too. It’s kinda hard to understand at first, so I’m gonna try and break it down into a clear, easy way. 

Let’s start with RGB.

RGB is an acronym for the colors in that group: red, green, and blue.  They’re most commonly used in photography, digital art, and any video or digital screen.

Speaking of digital screens, this is a pixel. Pixels are the tiny individual lights that make up all of the images on our screens. Pixels have 3 colors: red, green, and blue, and they’re used to create different colors. They do this by showing the RGB colors at different

 brightnesses to trick the eye into seeing other colors. For example, the color yellow does not exist on a screen. There are no yellow lights that create the color yellow on a screen. What you’re really seeing is a specific amount of red, green, and blue made to look like yellow.

RGB colors are what are called Additive Colors. The reason they’re described as additive is that these primary colors are added to each other or layered in varying amounts to make different colors, just like with screens and photos. When all 3 are added at 100% opacity, it appears as white. The main thing to remember about RGB is that RGB is always digital, and added to create colors.

Now onto CMYK.

Like RGB, CMYK is also an acronym for the colors in that group: cyan, magenta, and yellow. K is for black, which differentiates it from blue. CMYK are the colors that are used in printing. From posters to magazines to billboards, and any basic colored paperwork you’d print on an office printer.

Printers work by creating dots of cyan, magenta, yellow, and black inks to achieve different colors, much like how RGB uses its colors to achieve colors on screens. This photo is an example of printed dots to achieve different colors. This is a close-up I took of a package of AriZona fruit snacks. From a distance, there appears to be some maroon and orange on the package. But after zooming in, it’s visible that the orange is actually made up of yellow and magenta spots, and the maroon is a combination of magenta, a tiny bit of yellow, and some black spots to darken it.

CMYK is Subtractive Color. CMYK, by default, is 100% opacity. That means 100% cyan, 100% magenta, 100% yellow, and 100% black. Colors are made up of mixtures of CMY; and K is used to create value (darkness and light) in those colors. 

We know that dark-colored objects, usually black objects, get hot in the sunlight. This is because darker/black objects absorb more light waves. Whereas a red object absorbs all light waves except the waves that create the color red (magenta and yellow). Those colored light waves bounce off of the red object and into our eyes; that’s why we see color. The red we see is because of the absence of cyan bouncing into our eyes. A mixture of magenta and yellow with no cyan creates red. The cyan is “subtracted” from our view, hence the name Subtractive Colors. The main thing to remember about CMYK is that CMYK is always physical/printed, and subtracted to create colors. 

So what’s the difference?

Why aren’t screens made in CMYK? Or why isn’t paper printed in RGB? RGB is used when the color is coming from the light source. CMYK is used when an outside light source is shining on a colored object. RGB goes directly into our eyes. CMYK comes from a light source and bounces off of the object we’re looking at. 

Anyone who gives me a moment to talk about art knows that I’m a color nerd. I absolutely love talking about colors; specifically how our brains receive them and how they affect us. Be on the lookout for a later post(s) where I talk about the psychology of colors!