RGB vs CMYK vs HEX: Which Color Mode Should You Use?
Color settings are one of those things that seem simple until you actually need to use them. Then suddenly you're staring at acronyms like RGB, CMYK, and HEX, and you are wondering which one you're supposed to pick—and why it matters.
Let me break it down in a way that makes sense.
The basics: Additive vs subtractive color
RGB is additive. It starts with darkness (black) and adds light to create colors. Think of it like turning on colored lights in a dark room—the more lights you turn on, the brighter it gets. All colors combined = white light.
CMYK is subtractive. It starts with white (your paper) and adds ink to subtract light. The more ink you add, the darker it gets. All colors combined = black (or close to it).
This difference matters because your screen emits light (RGB) but your printer absorbs light (CMYK). That's why colors on your monitor don't always match what prints out.
RGB (Red, Green, Blue)
Best for: Web, digital screens, social media, presentations, anything viewed on a monitor
How it works: Combines red, green, and blue light in varying intensities to create millions of colors
When to use it:
Designing websites or social media graphics
Creating presentations
Any project that will only be viewed digitally
Microsoft Office documents (Word, PowerPoint, etc.)
Fun fact: Your phone, computer monitor, and TV all use RGB.
CMYK (Cyan, Magenta, Yellow, Black)
Best for: Anything that will be printed—business cards, brochures, posters, packaging
How it works: Printers mix tiny dots of cyan, magenta, yellow, and black ink on paper. The dots are either spread out or close together to create approximately 2 million+ colors.
When to use it:
Business cards
Brochures and flyers
Printed invitations
Packaging
Any physical printed material
Important: If you design something in RGB and send it to print, the colors will shift (usually getting duller) when converted to CMYK. Always design print projects in CMYK from the start, or at least check the CMYK preview before sending to print.
EX (Hexadecimal)
Best for: Websites, CSS, HTML, digital brand guidelines
How it works: A six-digit combination of numbers and letters (like #1A2B3C) that represents RGB values in a format web browsers understand
When to use it:
Building websites
Sharing brand colors with web developers
CSS styling
Digital design tools
Why I use HEX a lot now: Ever since Pantone stopped playing nice with Adobe applications (don't get me started), I've been using HEX colors more frequently. You can convert RGB to HEX using free online tools or design software.
Which color mode should YOU use?
Here's the simple rule:
Viewing on a screen? → Use RGB or HEX
Printing on paper? → Use CMYK
Brand consistency tip
When you're creating brand guidelines, provide color values in all the formats (RGB, CMYK, and HEX), so your logo looks consistent whether it's on your website, business cards, or promotional materials.
One last thing: Let your printer handle the conversion.
If you're sending files to a professional printer, ask them about color conversion. Many printers prefer to do the RGB-to-CMYK conversion themselves to ensure the truest, most accurate colors. They know their equipment and can adjust for how their specific printer reproduces color.
When in doubt: ask. Any good printer will be happy to tell you what file format they prefer.
Still confused about color settings for your project? I can help you get it right from the start.
Email me: aurelie@irisheyesdesign.com | Read more design essentials
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