CMYK vs. RGB
What Is the Difference Between CMYK and RGB?
RGB builds color from red, green, and blue light, which is how screens work. CMYK builds it from cyan, magenta, yellow, and black ink, which is how most printing works. Screens can show brighter colors than ink can print, so a design that glows on a monitor can come out duller on paper.
CE.SDK works with both. A design can use RGB and CMYK colors side by side, and the editor previews CMYK colors through a print profile, so users see a closer match to the printed result.
CMYK vs. RGB: How Do They Compare?
The two models mix color in opposite ways, which is why they suit different outputs.
| RGB | CMYK | |
|---|---|---|
| Made from | Red, green, and blue light | Four inks: C, M, Y, and K |
| How it mixes | More light, brighter color | More ink, darker color |
| Range of colors | Wider, including neons | Narrower |
| Made for | Screens, web, and video | Printing |
Why Do Colors Look Different When Printed?
RGB covers a wider range of colors than CMYK. When a file is converted for print, colors outside the CMYK range shift to a color the inks can make, and the brightest ones change the most.
Bright blues
Vivid screen blues often drift toward purple once they’re converted to ink.
Neon greens
Glowing greens have no ink equivalent and print noticeably muddier.
Saturated reds
Strong reds lose some of their punch and can turn warmer.
CMYK or RGB: Which Should You Use?
Match the color mode to where the design ends up. For one brand color that has to match exactly, a PMS color printed as its own ink is a third option. Check the print shop’s file guidelines too, because some shops convert RGB files themselves and a few prefer them.
Use RGB for
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Websites, apps, and social posts
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Video and on-screen presentations
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Large-format and print-on-demand shops that ask for it
Use CMYK for
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Offset and commercial print jobs
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Files a print shop wants in CMYK
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Brand colors given as CMYK values
How Do You Convert RGB to CMYK?
Convert with the print shop’s color profile, check the result on screen, and fix the colors that moved before the file goes out.
Get the shop’s profile
Ask the print shop which ICC profile its press uses, or pick from the common standard profiles for its region and paper. A conversion with that profile predicts the printed colors more closely than a generic one.
Convert and soft-proof
Convert the file, then preview it on screen the way it will print. Design tools call this a soft proof.
Fix the colors that moved
Bright blues, greens, and reds shift the most. Adjust them by hand until they look right in the proof.
Keep the RGB original
Colors lost in the conversion don’t come back when you convert again, so screen versions should start from the RGB file.
Which File Formats Support CMYK?
Screen formats such as PNG store only RGB, so a print file that needs CMYK goes out as a TIFF or as a print-ready PDF.
| Color mode | Used for | |
|---|---|---|
| JPEG | Usually RGB | Photos for screens |
| PNG | RGB only | Screen graphics with transparency |
| TIFF | RGB or CMYK | High-resolution print images |
| RGB, CMYK, or both | Files for the print shop |
How to Handle CMYK and RGB in CE.SDK
Pick colors in either mode
Fills, strokes, and shadows take RGB, CMYK, or spot colors, CMYK works in gradients too, and one design can mix them.
Preview with the printer’s profile
CMYK colors are shown through an ICC profile, and the default one models a US press. That’s also why rich black previews darker than plain black. Set the document’s profile to the one your printer supplies, for example for European coated paper.
Convert colors in code
Colors convert between RGB and CMYK in code. A round trip may not land on the same values, since each model has colors the other can’t show.
Export for screen or print
PNG, JPEG, and WebP exports are RGB, and any CMYK colors in them are converted with the document’s profile. For print, including web-to-print with CE.SDK, the Print Ready PDF plugin creates a CMYK PDF/X file, and in web and Node.js integrations a PDF export option keeps CMYK colors as CMYK.
CMYK and RGB in Print and Social Design
One design, two outputs
A marketing team builds an event flyer with CMYK colors for the print run, then exports the same design as an RGB image for social posts.
Brand palettes for both
A brand kit lists each company color twice, in RGB for screen templates and in CMYK for print templates, so every format starts from approved values.
FAQs
RGB. A hex code such as #FF0000 writes the red, green, and blue values of a screen color as hexadecimal numbers, so it describes light on a screen, not ink.
A screen gives off light, while paper only reflects it, and ink can't reach the brightest colors a screen shows.
Yes, but colors lost when an RGB file went to CMYK don't come back, so keep the RGB original for anything shown on screen.
Key. The name comes from the key plate in offset printing, the plate that prints the black ink.
Links
Documentation and references for this concept.
Related Terms
CMYK
The Cyan-Magenta-Yellow-Key(Black) subtractive color model used in professional print production, available in CE.SDK al…
PMS Color
An ink from Pantone's numbered color catalog, mixed to a fixed formula so it prints alike at every shop. In CE.SDK, it's…
Print-Ready PDF Checklist
What a PDF needs before a print shop can run it as is, from bleed and a safe margin to print-resolution images, CMYK col…
Rich Black
A deeper black made by printing cyan, magenta, and yellow under 100% black ink, used for large dark areas. A common buil…
Color Gamut
The full set of colors a screen, a press, or a color space is able to show or print. CE.SDK converts colors between the …