Color, Gradient and Image Fill

The Usage of the RGB and CMYK Color Models

Why do we have RGB and CMYK?

The RGB and CMYK color models have different approaches to create a color because they were designed for particular purposes.

In most cases, you can see an image on one of two types of surfaces. The first type includes screens of computers, phones, TV sets and so on. Their common feature is the capability to emit light. The RGB color model perfectly suits such devices because higher values of red, green and blue components make brighter colors in the same way as raising the screen brightness does.

An example of the second type is an image printed on white paper. Such a surface reflects light but cannot emit it. Areas with no ink remain white (the paper color). This corresponds to zero quantity of cyan, magenta, yellow and black inks. The more ink droplets cover a particular area, the darker and more saturated color we get. A mix of all inks, even without black, can completely screen the paper making a very dark color.

How to Choose a Color Model?

Let's begin with more simple cases when the purpose of your design is obvious. Graphics that are intended to be displayed on the screen should be RGB. That includes digital art, user interface designs for Web and apps, graphics to be used in video clips, content for social media and so on.

CMYK is often used for designs that will be printed. However this doesn't apply to all cases. Print shops may have their own requirements for customer's materials including color space, file format and others.

If your design is intended for displaying on a screen and for printing, you should choose RGB. It supports a wider color range and therefore better suits both use cases. So why use CMYK at all? This is necessary to be able to verify your design colors before printing. Once you convert an RGB design to CMYK, certain colors (often greens) can become dull. You might prefer to discover this sooner in order to make corrections in the design if necessary. If you send an RGB file to a printer, the printer driver will make the RGB to CMYK conversion for you. However you won't see the result until it is printed.

Unless you definitely know that you need CMYK, design in the RGB color space. Check how your design looks in CMYK if you care about how the design will look after being printed.

Switching Between Color Models

The New Document dialog lets you select a color model before a new document is created. Later on, use the Document panel.

In order to see how your RGB design looks in the CMYK color space, temporarily select CMYK in the Document panel. Then you can switch back to RGB.

Note that each color model comes together with a list of supported color profiles. If you are not familiar with profiles, keep the default one.

Which of the File Formats Support CMYK?

Since RGB is supported by barely all graphic file formats, let's pay more attention to CMYK.

PDF is the most popular format for CMYK because it also supports multi-page documents, it is capable of containing vector elements and text. The EPS format has capabilities similar to PDF. Among raster formats, TIFF is one that supports CMYK.

Color Profiles

Different devices (e.g., computer display or phone screen) may reproduce the same color with slightly different tints. In order that colors look uniformly, manufacturers calibrate their devices (monitors, printers, scanners) and save that information as a device's profile.

A color profile can be embedded into a graphic file to ensure that the image looks the same on different devices.

To select a new profile to your document, use the Document panel.