Light versus color: two opposite systems
The core of the difference: screens mix light, print mixes color.
- RGB (additive): a screen emits red, green, and blue. All three together make white, none makes black. More light = brighter — which is why a screen can glow.
- CMYK (subtractive): on paper sit cyan, magenta, yellow, and black (key). Each absorbs part of the incoming light. All together make (theoretically) black; no ink lets the white paper show. Paper can't glow — it only reflects.
Everything else follows from this physical opposition: RGB can display colors that CMYK can't print.
Which colors get lost
The CMYK print gamut is smaller than the RGB screen gamut — especially for bright, saturated tones:
- Vivid orange and neon green — the most obvious losers.
- Rich, glowing blue — often turns purplish or duller.
- Punchy pink and intense turquoise.
When converting to CMYK, these colors are "pulled back" to the nearest printable tone — they look more muted. That's not a bad printer, it's physics. The related topic for screen color spaces is in Color spaces explained.
How to avoid the disappointment
- Soft-proof in CMYK on screen. Layout programs offer a "soft proof" view with the print profile — then you see the color shift before printing and can react.
- Choose colors deliberately. If you know it's going to print, don't reach for screen neon in the first place; pick tones CMYK reproduces cleanly.
- Use the print shop's profile. Online printers provide ICC profiles (often "ISO Coated" or similar). Convert and check against exactly that.
- Consider spot colors. If an exact bright color is mandatory (a brand color), Pantone/spot colors exist — a separate print run with exactly that ink, outside the CMYK four. Costs extra, but hits the mark.
Do I always have to convert myself?
No — it depends on the print route:
- Professional offset print: supply CMYK, ideally with the required profile.
- Online printers: often accept RGB and convert themselves — convenient, but with less control over the color shift.
- Home inkjet: send RGB, the driver does the rest; here the right paper matters more than the color mode.
In short
- Screens mix light (RGB), print mixes color (CMYK) — RGB shows more.
- Vivid orange, neon green, punchy blue lose the most.
- Soft-proof and pick print-safe colors upfront.
- Spot colors for a mandatory exact brand color.