About CMYK Color

CMYK color is a color model that represents colors with four components: cyan, magenta, yellow, and black (key plate). It is mainly used in printing and desktop publishing, and is based on subtractive color mixing, where colors are produced by layering inks.

In CMYK, each component is represented in the range from 0% to 100%. In general, C, M, and Y represent the color tone, while K represents the amount of black. When all components are 0%, the color is white; when K is 100%, the color is close to black.

To include transparency, add an alpha value. For example, semi-transparent red can be represented as device-cmyk(0% 100% 100% 0% / 0.5).

Color profiles

DenCode lets you choose from several color profiles. The supported color profiles are listed below.

CMYK colors using an “ICC profile” or “approximate color profile” are represented in the CSS custom color space format color(--profile C% M% Y% K%). To use them in actual CSS, specify the corresponding ICC profile with @color-profile.

@color-profile --swop2013-c3 {
  src: url("path/to/SWOP2013C3_CRPC5.icc");
}

.foo {
  background-color: color(--swop2013-c3 0% 100% 100% 0%);
}

Approximate color profiles calculate approximate CMYK colors based on published Characterization data. Therefore, even when a similar ICC profile is used with CSS @color-profile, the displayed color may differ slightly.

Difference between CMYK and RGB

CMYK is a subtractive color model for printing inks. In contrast, RGB is an additive color model for light, such as displays. Even for colors that look the same, CMYK and RGB component values can differ greatly.