RGB vs CMYK: getting screen colors to print correctly

By the 000098 editorial team · Updated October 10, 2026 · 7 min read

A brand blue that glows on a laptop can turn dull or purple on a business card. The reason is physics: screens and printers make color in opposite ways.

RGB is additive light

Screens start black and add red, green and blue light. More light means brighter colors, and all three at full strength make white. Screens can show very saturated blues and greens because they emit light directly.

CMYK is subtractive ink

Printers start with white paper and add cyan, magenta, yellow and black (K) inks, each of which absorbs some light. More ink means darker colors. The range of colors ink can reproduce (its gamut) is smaller than a typical screen's, especially for vivid blues, greens and oranges.

Example: #000098

A naive formula converts #000098 to CMYK 100 / 100 / 0 / 40. In practice, 100% cyan plus 100% magenta plus 40% black is a very heavy ink load (240% total) and may print muddy or purple depending on the press. A printer using a proper ICC profile will often produce a different, better recipe. Treat online CMYK numbers as a starting point, not a final spec.

Conversion checklist

1. Ask your printer which profile they use (for example, a coated or uncoated paper profile) and convert with it in your design software.
2. Request a hard proof for anything you will print in volume.
3. Consider spot colors for critical brand colors on stationery and packaging; a spot ink matches more consistently than a CMYK mix.
4. Watch total ink coverage. Many presses recommend staying under 280–320%.
5. Use rich black (for example 60/40/40/100) for large black areas, but plain 100% K for small text.
6. Paper matters. Uncoated paper absorbs more ink, so colors look darker and less saturated.

Document both

Your style guide should list separate, tested values for screen (HEX/RGB) and print (CMYK and any spot color). Do not let anyone convert on the fly from the hex code.