About the CMYK to RGB
This tool converts CMYK ink percentages to RGB, so a colour specified for print can be previewed or used on screen. Write each colour as four percentages in the order cyan, magenta, yellow, key, with one colour to a line.
The arithmetic is the exact inverse of the screen-to-print step: a channel is 255 multiplied by one minus the ink, multiplied again by one minus the key. Because K scales all three channels by the same factor, raising it darkens the colour evenly while the ratios between the inks, and so the hue, stay where they were. That makes K the handle to reach for when a print colour is nearly right but sits too heavy.
One consequence worth knowing is that different ink mixes collapse onto the same screen colour. Both cmyk(0%, 0%, 0%, 100%) and cmyk(100%, 100%, 100%, 100%) arrive here as black, although on paper the second floods the sheet with ink and would be rejected by any press for exceeding its total ink limit. The formula has no notion of ink limits, stock or an ICC profile, so it will happily accept a combination that cannot be printed.
To convert RGB to CMYK, use RGB to CMYK; for HEX output, follow with RGB to HEX or use the Color Converter.
How to use
- Paste cmyk() values, one per line.
- Copy the rgb() values.
Common questions
- How do I get HEX from CMYK?
- Convert here to RGB, then use RGB to HEX, or paste the CMYK into the Color Converter for all formats.
- Is the colour exact?
- It is an approximation; print and screen gamuts differ.
- What format should I enter?
- Cyan, magenta, yellow and key as percentages, such as cmyk(84%, 0%, 45%, 24%). The percent signs are optional.