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Beginner • 10 min read

RGB vs CMYK

Understand the critical differences between RGB and CMYK color models and when to use each for best results.

🖥️ vs 🖨️ Screen vs Print

RGB and CMYK are the two most important color models in design. RGB is for digital screens, while CMYK is for print. Understanding when to use each prevents colors from looking different than intended.

Quick Comparison

RGB
  • Full Name: Red, Green, Blue
  • Type: Additive color model
  • Use: Digital screens, web design
  • Colors: 16.7 million possible
  • Format: rgb(255, 0, 0), #FF0000
CMYK
  • Full Name: Cyan, Magenta, Yellow, Key (Black)
  • Type: Subtractive color model
  • Use: Print design, physical media
  • Colors: Thousands (limited)
  • Format: cmyk(0, 100, 100, 0)

How RGB Works

RGB is an additive color model used for screens. It works by adding colored light together. Screens have red, green, and blue pixels that light up at different intensities to create colors.

Additive Color Mixing

Colors get lighter as you add more light:

Red + Green = Yellow
Green + Blue = Cyan
Blue + Red = Magenta
All together = White
When to Use RGB
  • ✓ Website design
  • ✓ Mobile apps
  • ✓ Digital graphics
  • ✓ Social media images
  • ✓ Video and animation
  • ✓ Digital photography
  • ✓ Email marketing
  • ✓ Any screen-based design

Key Point: Use RGB/HEX for anything displayed on a screen. This is the default for most design software and web development.

How CMYK Works

CMYK is a subtractive color model used for printing. It works by using inks that absorb (subtract) light. The more ink you add, the darker the color becomes.

Subtractive Color Mixing

Inks absorb light - combining them creates darker colors:

Cyan ink absorbs red
Magenta ink absorbs green
Yellow ink absorbs blue
Key (Black) adds depth
When to Use CMYK
  • ✓ Business cards
  • ✓ Brochures and flyers
  • ✓ Packaging design
  • ✓ Magazines and books
  • ✓ Posters and banners
  • ✓ Clothing and merchandise
  • ✓ Any printed material
  • ✓ Physical products

Key Point: Design in CMYK from the start for print projects. What you see on screen may not match what prints due to gamut differences.

The Gamut Problem

Not all RGB colors can be reproduced in CMYK. This is called gamut difference. Some vibrant RGB colors appear duller when printed.

What Can Go Wrong

Bright Red → Muddy Red

Pure RGB reds lose their vibrancy when converted to CMYK

Neon Blue → Dark Blue

Bright, electric blues become much darker in print

Lime Green → Olive Green

Bright greens turn more yellow and dull

💡 Pro Tip

Always check your colors in CMYK mode before sending to print. Use "gamut warning" in Photoshop to identify problematic colors.

Color Conversion Examples

Here's how colors convert between RGB and CMYK, along with HEX codes for web use.

ColorRGBHEXCMYK
Red
rgb(255, 0, 0)#FF0000cmyk(0, 100, 100, 0)
Green
rgb(0, 255, 0)#00FF00cmyk(100, 0, 100, 0)
Blue
rgb(0, 0, 255)#0000FFcmyk(100, 100, 0, 0)
Yellow
rgb(255, 255, 0)#FFFF00cmyk(0, 0, 100, 0)
Purple
rgb(128, 0, 128)#800080cmyk(60, 100, 0, 40)
Orange
rgb(255, 165, 0)#FFA500cmyk(0, 50, 100, 0)

Best Practices

For Digital Design
  • ✓ Always design in RGB for screens
  • ✓ Use HEX codes in CSS (#FF0000)
  • ✓ Test on multiple devices
  • ✓ Consider dark mode variants
  • ✓ Ensure sufficient contrast
  • ✓ Use sRGB for web compatibility
For Print Design
  • ✓ Design in CMYK from the start
  • ✓ Use Pantone for brand colors
  • ✓ Request printed proofs
  • ✓ Check gamut warnings
  • ✓ Use 300 DPI minimum
  • ✓ Convert text to outlines

Key Takeaways

  • RGB is additive for screens (light), CMYK is subtractive for print (ink)
  • Always use RGB/HEX for web design and digital projects
  • Design in CMYK from the start for any print project
  • Not all RGB colors can be printed - check gamut before printing
  • Always request a printed proof for important print jobs

Test Your Knowledge

RGB vs CMYK Quiz
第 1 题,共 5 题

Which color model should you use for a website design?

RGB vs CMYK - Color.edu.kg | Color.edu.kg