Well, hello there! Today we’re going to talk about something that some may find interesting (And yet those familiar with it will probably already know): Just how does your copier make so many amazing colors from just four colors?

As kids, we probably learned a lot about what colors can be combined to make what other color. Your copier uses this same principle to make various, amazing colors from just Cyan, Magenta and Yellow.

“But wait, aren’t the main colors Red, Green and Blue??” Well, yes, but that’s in the RGB color table. Copiers and printers use the CMYK color table. RGB is used on digital displays where various levels of each color of light is used to create other colors. CMYK is used by printers and copiers to produce full color copies. (There is also the RYB (Red-Yellow-Blue) color table, but that’s mostly only used in the art world.)

The key difference here is HOW these colors are mixed. RGB uses a process called Additive Color Mixing, where CMYK uses Subtractive mixing. It basically means exactly what you are thinking it means. One adds the colors together to get the resulting color, and the other one subtracts to get the resulting color.

As RGB is mostly a light-based color system, figuring this one out is pretty simple. Let’s take three colored spotlights, One red, one green, and one blue, and point them directly at a white wall. Turn them all on at once at full brightness, and you’ll end up getting a white light. Now, turn off the GREEN light, leaving RED and BLUE on. You’ll end up getting a magenta light out of this. Turn on the GREEN light but turn off BLUE. You’ll get a yellowish light. Of course, do this with GREEN and BLUE, and you’ll get Cyan.  

Now, turn on all 3, but start dimming them to various levels. You will start getting a mix of other colors. (Set red and blue to appropriate levels to get somewhat of a good purple color. You can easily experiment with this in many different paint and photo applications, and if you’re someone with an RGB lit computer case, you can experiment here too!)

RGB numeric values go from 0 (black) to 255 (Full Output), set up in the order of R-G-B.

Red: 255-0-0
Green: 0-255-0
Blue: 0-0-255
Black: 0-0-0 (Total darkness)


Now, let’s look at CMYK. CMYK is what your color copier will use. CMYK stands for Cyan, Magenta, Yellow and Black. (K is used to denote black. While it is not considered a color, it is treated as such in digital printing. The “K” label for black stands for “key”). Unlike RGB, CMYK numeric values are from 0-100, and are arranged in color order (C-M-Y-K). Let’s look at how these work and how they are noted:

Cyan: 100-0-0-0
Magenta: 0-100-0-0
Yellow: 0-0-100-0
Black: 100-100-100-0

You may be wondering why Black is 100-100-100-0: Because CMYK is a subtractive color system, opposite of RGB, Color mixes are obtained by DARKENING the colors rather than making them brighter. While all 3 colors can be mixed together to make black, In the case of your copier, Black is created from a dedicated black toner container. Some printers do use the color inks/toners to make black happen however. (Which is often times WHY your printer will complain about a color being empty despite you not wanting color at that time)

So let’s begin on our CMYK color creation journey. If we combine Magenta and Yellow, we will end up getting Red (Noted in this system as 0-100-100-0).

Likewise, if we combine Yellow with Cyan, we will get Green (100-0-100-0)

Now, let’s flip that and put Magenta and Cyan together. With that, we end up with Blue (100-100-0-0)

Lastly, if we throw all 3 together, we get black. (100-100-100-0)

Of course, you can also vary the color levels to make even more colors.

Notice what we just did in these examples. If you have a keen eye for details, you’ll see that we just created RGB colors from CMYK. In the case of CMYK, we are darkening the primary colors to create other colors, unlike in RGB where you brighten the primary colors. CMYK color subtraction works by putting one color on top of another on a sheet of white paper. Unlike RGB, which is produced with light, CMYK works by absorbing certain wavelengths of light, removing that particular color from view of the human eye.

Of course, if you put all 3 together on a page, you’re just going to get black.

Basically, it’s just like that time you learned about mixing colors in school, but in a bigger picture. Your copier is doing all the mixing! If it wasn’t for this, your copier would need dozens of different toners, which would require about as much space as the old UNIVAC.

It is that magic and technology, that helps your copier produce a wide array of glorious colors from just four toners.