Hello guys I am Vaibhav and in this article I am going to teach you the meaning of RGB and CMYK in depth. Last time I discussed about Creating Ghostly Blurred Text in Photoshop which is an extremely important tutorial for graphic designers.
Basically there are two type of color mode. one is additive while other is subtractive. The monitor or screen we use additive color and the printing press etc. uses subtractive color mode.
Stock: http://lynnwest-stock.deviantart.com/art/Dark-Tunes-19-168804751 (unedited version)
What is additive color system
You might have heard that color is composed of three basic colors that is red, green and blue. When we add these three color we can get all the possible colors. This is called additive color system.
To select the RGB mode go to image>mode>RGB. In the above picture you can see by combining the basic 3 color(red, green and blue) we can get all possible color. In Photoshop you can adjust the contribution of the 3 color on the scale of 0 to 255. You can see the contribution of each color in “channel”. Go to window>channel. There you will have 4 channel i.e RGB(stands for red, green and blue), Red channel, Green channel and blue channel.
You can see all 4 channel there. I have selected RGB hence it will how the entire color that is formed using red, green and blue.
Above shown picture shows the contribution of red color. The white area shows the maximum contribution of red color while the black area shows the minimum contribution of red color. You might have observed the face of the girl has suddenly got so much bright as well as much smoother. During the retouching of skin this red channel helps us a lot because it gives perfect skin . You can see an example here. By default the channel will be shown in grayscale format. You can change it by going to edit>preference>interface.
And then click on “show channel in color”. This will show your channel in color rather than grayscale.
In the green channel you can see that sky has got bit lighter this is because the presence of green color in sky is more than red color. You might have also observed that the skin has become dark after selecting green channel.
As I said earlier that the white area shows the maximum contribution of blue color in blue channel and the sky is of blue color so it was expected that the sky would be white when you select blue channel.
RGB mode is best for photo processing as well as graphics designing. IT also gives you more combination of color as compared to CMYK
What is subtractive color system
Now you know what is additive color. Subtractive color is just opposite of additive color system. It is the combination of light that is reflected(that you can see) with the absorbed light(that you cannot see).
In the subtractive system, different-colored inks absorb different-colored light. For example, cyan ink absorbs red light and reflects green and blue light back at you, so you see a mix of green and blue—in other words, cyan. Similarly, magenta ink absorbs green light and reflects red and blue light; in other words, magenta. One last example: A mix of cyan, magenta, and yellow ink absorbs most of the primary colors—red, green, and blue—so you see what’s left over: dark brown.
CMYK(cyan, magenta, yellow and black) comes under the category of subtractive color. You can change the mode to CMYK by going to image>mode>CMYK.
You can see the cyan, magenta, yellow and black in the above 4 pictures. It is mainly used for printing purpose. One major drawback of this mode is that it gives us less combination of colors as compared to RGB. So it’s best for you to choose RGB mode than change to CMYK for printing purpose. Add on CMYK mode adds a little bit noise to your photo.
And we are done here. Read my next tutorial where I will be discussing about Channels in Photoshop. Thank you for reading this. Hopefully we’ll meet again four days.