Why do we use CMYK instead of RGB? (Very colorful post)

maybe you too wondered why there is written CMYK on printers. If you have printer or you found out what it means you too know that it is abbreviation for: Cyan, Magenta, Yellow (and K which I will tell later).

What CMY stands for?



Those are the colors that you have to fill inside the machine to print you stuff. Sure this is ok, but why do not we use RGB (red, green, blue)? It seems to be used everywhere so why not in printers?

I thought this because I was thinking that from RGB you can get any color, and sure you can, but only in additive process. Such a process happens for example with light, white light is made up of many different parts with different wavelengths that ADD up. So what does mean that something is red(?), well it reflects only red light absorbing the rest. If you put there blue the material will be even more darker because it will reflect only the combination of blue and red. If you combine everything it would not reflect at all, the object would be black.

This is an example of substractive process with colors. You can see that RGB is darker since you will get it by substracting CMY.

So what you want to do is to start with lighter colors, those are cyan, magenta and yellow. They too are able to add up to all other colors + lighter than RGB in this subtractive form. Even then colors are not perfect in printers so you can not add up to some, bright red, blue  and green wont be displayed very well.







What the “K” stands for? It stands for “Key” which is the color black (it is the KEY thing). While CMY can add up to black, it would not be very pure since the colors can not be clean, it was decided that there will be black added because in most texts black is used. The letter “K” was used because “B” was already used in the RGB model.


PS: check out these two links about colors shared by Jim Ruebush, they are truly amazing:
1) 2)


What is the color of Universe?

today I want to write about the average color of the Universe.

The average color of the Universe is not black. I mean, when you look at the sky in night it seems that there is black everywhere, but that is actually no color. When we speak about color we say that something is red, that means that it reflects red light.

Right, light, but when there is nothing shining it does not have any color because it can not reflect anything.

The average color of the Universe was found in 2002, year before the same team discovered the color which you can see below but it was corrected several months later because there was mistake in the software.

So how do you find such a color? Well you take the color we see of various galaxies and stars and so on and make the average of all the photons wavelengths creating the color which you can see below:

This color gets redder over time as there are more red stars in the Universe. In RGB this color is: 255,248,231.

Meet the color of the Universe, Cosmic Latte.


Those two color were taken from here.

PS: Next week there wont be practicly any posts since I will be away learning some math.