The short version
- RGB makes colour by adding red, green and blue light, and is used for screens; CMYK makes colour by layering cyan, magenta, yellow and black ink on paper.
- The range of colours CMYK can print is smaller than the range screens can show, so very bright RGB colours have to be pulled in when they are printed.
- Saturated greens, blues, oranges and neon pinks shift the most when converted to CMYK.
- Paper changes colour too: uncoated stock absorbs more ink and prints softer and darker than coated stock.
- Design in RGB for screens, check or convert to CMYK with your printer's profile before print, and ask for a proof when colour matters.
On this page
RGB vs CMYK is the difference between light and ink. A screen makes colour by adding red, green and blue light, starting from black. A printer makes colour by laying cyan, magenta, yellow and black ink on white paper, each layer absorbing some light. Ink simply cannot reach some of the colours a glowing screen can, so when a bright RGB design is printed, those colours get pulled in to the nearest printable version. That is why your neon green came back as a polite leaf green.
How RGB and CMYK make colour
RGB: light
- Additive: red, green and blue light combine
- All three at full strength make white
- None makes black
- Used by phones, monitors, TVs and projectors
- Written as hex,
rgb(),hsl()oroklch()
CMYK: ink
- Subtractive: each ink absorbs part of the light
- No ink leaves the paper white
- Cyan, magenta and yellow together make a dark brown, so black ink is added
- Used by most commercial and office printing
- Written as four percentages, such as C0 M60 Y90 K0
The K in CMYK stands for key, the plate that carries detail, which in practice is black. Black ink gives sharp text and deep shadows more cheaply and cleanly than stacking the other three inks.
Gamut: the colours ink can't reach
A gamut is the full range of colours a device can produce. The standard screen space, sRGB, overlaps most of a typical CMYK press gamut but reaches further in bright, saturated areas. Some CMYK colours, such as certain deep cyans, sit slightly outside sRGB the other way, but the big losses go from screen to paper.
What tends to happen in CMYK
What tends to happen in CMYK
What tends to happen in CMYK
What tends to happen in CMYK
What tends to happen in CMYK
What tends to happen in CMYK
What tends to happen in CMYK
Paper changes colour too
The same CMYK file prints differently on different paper. Coated papers hold ink on the surface, so colours stay crisp and saturated. Uncoated papers soak ink in, so colours look softer, slightly darker and less contrasty, and fine detail spreads a little. Recycled and cream stocks add their own warmth. If you are choosing between a glossy flyer and a textured invitation, expect the textured one to look calmer.
Coated paper
- Ink sits on the surface
- Colours stay crisp and saturated
- Fine detail and small text stay sharp
- Suits flyers, brochures and photo heavy work
Uncoated paper
- Ink soaks into the fibres
- Colours look softer, darker and flatter
- Detail spreads slightly, so avoid hairline type
- Suits stationery, invitations and a natural feel
How to convert RGB to CMYK without nasty surprises
- 1
Ask the printer first
Find out whether they want RGB or CMYK files, which colour profile they print to, and their preferred black. Many modern printers accept RGB PDFs and convert themselves with their own profile.
- 2
Design at print size and resolution
Work at 300 dpi at the final size, for example 2480×3508 px for an A4 poster or 1050×600 px for a business card. DPI vs PPI explains the numbers.
- 3
Soft proof before you convert
Most professional tools can preview the file in the printer's CMYK profile. Look for colours that shift and adjust them yourself rather than letting the conversion decide.
- 4
Pull the brightest colours in by hand
Lower the saturation of neon greens, blues and pinks slightly, or deepen them, until the screen preview and the CMYK preview look close.
- 5
Use rich black for big dark areas
Black ink alone looks dark grey across large areas. Ask the printer for their rich black mix, and keep small text in black ink only.
- 6
Add bleed and get a proof
Extend the background past the trim, usually 3 mm, and request a printed proof whenever colour really matters. Bleed and margins covers the setup.
Design at the final print size: an A4 poster is 2480×3508 px at 300 dpi. Soft proof it in the printer's profile before you send it.
When to use RGB and when to use CMYK
Use CMYK for
Use CMYK for
Use CMYK for
Use CMYK for
Keep one master version of your brand colours in RGB for screens and a separately checked CMYK version for print, and write both into your brand style guide. Gradients deserve extra care in print because subtle steps can band; print gradients has the details.
In Gradiently, Pro exports include a print PDF with bleed and crop marks, so a poster or flyer leaves the Studio ready for the printer's checks; print ready PDFs covers what printers look for. Agree colour conversion with the printer and you will get far fewer surprises.
Questions people ask
What is the difference between RGB and CMYK?
RGB mixes red, green and blue light for screens. CMYK layers cyan, magenta, yellow and black ink for print, and can't reproduce some of the brightest screen colours.
Why do my colours look different when printed?
Ink has a smaller colour range than a screen, paper absorbs and reflects light differently, and screens are usually brighter than paper. Saturated colours shift the most.
Should I design in RGB or CMYK for print?
Ask your printer. Many accept RGB and convert with their own profile; if they want CMYK, soft proof and convert yourself so you can adjust colours that shift.
Which colours don't print well in CMYK?
Neon greens, electric blues, bright oranges, hot pinks and vivid violets lose the most intensity. Muted and pastel colours print closest to the screen.
Is hex RGB or CMYK?
Hex codes are RGB. A hex value is simply the red, green and blue amounts written in base 16.
Written by Gradiently
The team behind Gradiently, a design tool built around Marks: living gradients that make everything you design look like yours.
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