RGB and CMYK what they are and how to use them

The difference between RGB and CMYK is a topic with which you think that you are familiar with, but which in practice impacts your business on a day-to-day basis. An impact that ranges from having to become familiar with it to work smoothly to all those problems that inconsiderate management can create.

I think it has happened to everyone to have received a nasty surprise after the press or having had to modify a project in extremis because we had chosen an incorrect range.

This is why, beyond the theoretical knowledge of what the different color methods are and how they work, it is also important to understand how and when to use them.

But let's start with the definitions.

RGB, CMYK: what do these abbreviations mean?

When we talk about RGB or CMYK we use acronyms that indicate a series of colors:

• Red, green and blue for RGB ( red, green, blue )
• Cyan, magenta, yellow and black for CMYK ( cyan, magenta, yellow, key black )

In both cases, these are basic colors which, when mixed, allow the desired tint to be obtained in each of the two color methods.

So both RGB and CMYK are color modes :‌ systems by which different colors are classified and can be replicated exactly.

New project RGB or CMYK?

When you're about to start a new project, one of the very first things to do is to choose which color mode to work with .

RGB and CMYK are based on two different ways of obtaining color. RGB refers to the colors created by three beams of colored light (red, green and blue), a bit like screens. With CYMK , on the contrary, we refer to color as matter , for example in the field of graphic design, they are the inks of typographic printing (cyan, magenta, yellow and black), with which color is obtained.

This results in a different gamut width . In summary, the RGB gamut has more colors than the CMYK gamut. And this is precisely the reason why it is important to start with the most suitable color method.

How do you know which color mode you're working with? Or how can you set it? Is simple:

• In Illustrator, select File > Document Color Mode in the menu
• In Photoshop, select the Image > Mode menu
• In Indesign select Edit > Convert to Profile in the menu.

Are you wondering how to choose the right color method?

When to choose RGB or CMYK

The substantial difference between the two color methods lies precisely in the means by which the color is created:‌ beams of light in the case of RGB, pigments in the case of CMYK.

Consequently, when you start a project, the right thing to do is to choose the color method based on the medium through which the project will be disseminated and used . Let's see it better with examples.

When to use RGB color mode

The RGB‌ method is to be preferred whenever the project will be used through screens .

We therefore have a great variety of uses:

• app
• graphics for social media (posts, profile photos, covers)
• graphics or photos for websites
• web advertising
• graphics for television / cinema

For all these purposes there are export formats which generally constitute a standard for the various publishing platforms and which are also the most suitable for applying the RGB color method .

In particular:

• jpg
• png
• gif
• psd
• webp

When to use the CMYK color mode

The CMYK color method , or four-colour process, simulates in the digital environment what really happens in the printing phase , when more or less small dots of ink in four basic colors are combined to form the desired colour.

Consequently, there is no reason to work on a project setting the CMYK method if that project is not going to be printed.

On the contrary, as we have anticipated, for all those graphics that will then be reproduced on paper , or on fabric and other surfaces , it is very important to apply the four-color process to the project before it goes to print. In particular it is recommended for:

• business cards, letterhead, brochure, flyer
• posters, billboards, roll-ups, pop-ups
• merchandising
• packaging, labels
• flyers, posters, menus, press releases

Choosing the correct color mode is important because there is no perfect match between RGB and CMYK . When passing from the first to the second color method it almost always happens that the colors become less vivid , more dull. As if a gray filter had been applied to the whole project.

If instead from the beginning you work in four colors it is possible to get around this problem . On the one hand, in fact, a careful calibration of each single color in CMYK allows you to make the most of all the possibilities of this range. On the other hand, you can resort to expedients typical of the composition to obtain the desired effect, such as for example combining a complement to the color you want to make it appear more vivid.

As far as formats are concerned, the most suitable ones for exporting your projects made with the CMYK color method are

• PDF
• TO THE
• EPS

When to use both

It's not at all uncommon, actually, that you have to work on projects where both RGB and CMYK would be indicated.

Think for example of all the times you work on a brand identity : it is obvious that the company logo, as well as all the other graphic elements, will be used both on printed material and in digital form.

Or the graphics that advertise an event will be used both for billboards and on social networks.

What to do in these cases?

The advice is to work with both color modes , using the conversion functions from one to the other that you find in the most common software, such as Adobe Creative Cloud, and make the necessary corrections before exporting.

In some situations it may also be necessary to associate RGB‌ and CMYK with a third color method , the so-called spot colors . In this way it is possible, for example, to overcome some problems linked to the more restricted gamut of the four-colour process.

Conclusions

In summary, if the file is functional for a video display (like an element of a website), the RGB system is perfectly fine because it offers a wider range of shades from which to choose and indulge. If, on the other hand, the file is to be used for printing any product, it is good practice to convert it to CMYK to avoid unpleasant surprises once the job is done.

Professional graphics programs offer the possibility to choose which profile to work with, so just one click is enough to select it. These software (such as Adobe Photoshop or Adobe Illustrator) also allow you to convert a file from RGB to CMYK: if you carry out this operation you will be able to see firsthand the chromatic variation between the two profiles.

Then remember that in addition to the color method, the choice of profile is also very important, if you want to know more we talked about it in this article