RGB and CMYK are two different color models that are used in digital and print design respectively. They have key differences that impact how colors are displayed and printed.
What is RGB Color?
RGB stands for Red, Green and Blue. It is an additive color model that is used for color displays like computer monitors, TV screens and other digital media.
In the RGB model, colors are produced by combining different intensities of the three primary colors – red, green and blue. By mixing varying intensities of these three colors, a wide range of colors can be produced. For example:
- Red + Green = Yellow
- Green + Blue = Cyan
- Blue + Red = Magenta
RGB uses numerical values to define colors. The intensity values for each primary color ranges from 0 to 255. Which means there are 256 possible values for each primary color. By mixing the RGB values, over 16 million color combinations can be produced.
Some key points about the RGB color model:
- It is an additive color system – colors are produced by combining red, green and blue light.
- Uses Red, Green and Blue as primary colors
- Great for displaying colors on digital screens
- Colors are defined using numerical RGB values from 0 to 255
- Capable of producing over 16 million color combinations
What is CMYK Color?
CMYK stands for Cyan, Magenta, Yellow and Black. It is a subtractive color model that is used for color printing.
In the CMYK model, colors are produced by mixing different percentages of these four process colors:
- Cyan
- Magenta
- Yellow
- Black
These four colors are called ‘process colors’ because they are the primary pigments used in the printing process. By mixing different percentages of cyan, magenta, yellow and black, a wide range of colors can be reproduced. For example:
- Cyan + Magenta = Blue
- Cyan + Yellow = Green
- Magenta + Yellow = Red
In CMYK, color definitions use percentages. Each color is represented by a percentage value ranging from 0% to 100%. By mixing these CMYK percentage values, a broad spectrum of colors can be produced for printed materials.
Key characteristics of the CMYK model:
- It is a subtractive color system – colors are produced by absorbing select wavelengths of light and reflecting the rest back to our eyes.
- Uses Cyan, Magenta, Yellow and Black as primary colors
- Great for color printing on paper and other physical materials
- Colors are defined using CMYK percentage values from 0% to 100%
- Capable of reproducing a wide range of colors for print
Key Differences Between RGB and CMYK
While both RGB and CMYK can produce a wide range of colors, there are important differences between the two color models:
| RGB | CMYK |
|---|---|
| Additive color model | Subtractive color model |
| Light is emitted to produce colors | Light is absorbed and reflected to produce colors |
| Used for digital displays and screens | Used for print materials and physical surfaces |
| Uses red, green and blue as primary colors | Uses cyan, magenta, yellow and black as primary colors |
| Colors defined by 256 RGB values | Colors defined by CMYK percentage values |
| Capable of producing over 16 million colors | Capable of reproducing a wide range of colors for print |
Here are some key differences explained in more detail:
Additive vs Subtractive Color
RGB is an additive color model where light is emitted to produce colors. The primary colors (red, green and blue) are combined to create the desired color. The more color that is added, the closer to white the color becomes.
CMYK uses subtractive color where colors are produced by absorbing select wavelengths of light and reflecting the rest back to our eyes. The primary colors (cyan, magenta, yellow and black) subtract brightness to create color. The more color that is subtracted, the closer to black the color becomes.
Light Emission vs Light Absorption
In RGB, the screen emits varying intensities of red, green and blue light to create colors. The combination of this colored light results in the final color that is emitted from each pixel.
In CMYK, the paper or substrate absorbs certain wavelengths of light and reflects the rest back to our eyes. Each of the primary colors (cyan, magenta, yellow and black) absorbs certain wavelengths and reflects back the remaining light, creating the final color we see.
Digital Display vs Print Reproduction
RGB is designed for displaying colors using light emitting devices like computer monitors and TV screens. It can produce a very wide range of colors capable of representing the visible spectrum that humans can see.
CMYK is designed for reproducing a wide range of colors when printing on paper or other physical materials. However, it has a more limited color range compared to RGB and some colors like bright reds, greens and blues cannot be perfectly reproduced in CMYK.
Primary Colors
The primary colors in RGB are red, green and blue. Varying intensities of these three colors of light are combined to produce a wide range of colors.
In CMYK, the primary colors are cyan, magenta, yellow and black. These four process colors are the main pigments used for printing color. Combining these pigments in different percentages allows for reproducing many colors.
Color Definitions
In RGB, each primary color is assigned a value from 0 to 255. So red, green and blue each have 256 possible intensity values. By combining RGB values, over 16 million color combinations can be defined.
CMYK uses percentage values from 0% to 100% for each primary color. Different combinations of these CMYK percentages allow for defining a wide color gamut for print.
Number of Colors
RGB is capable of producing over 16 million color combinations by mixing the red, green and blue primary colors.
While CMYK can reproduce a wide range of print colors, it has a more limited gamut compared to RGB. Some highly saturated colors like neon greens, reds and blues cannot be fully reproduced in CMYK.
Conversion Between RGB and CMYK
Since RGB and CMYK have different color capabilities, colors defined in one model need to be converted appropriately to the other model for accurate rendering in print or digital media.
Conversion from RGB to CMYK involves determining what combination of cyan, magenta, yellow and black pigments can best approximate the RGB color. This can be done using color profiling software.
When converting CMYK values to RGB, the percentage values need to be mapped to appropriate RGB intensities. This process is called color separation. Again color profiling tools are used to achieve accurate conversions.
Here are some key considerations when converting between the two color models:
- Some RGB colors fall outside the CMYK gamut, so exact conversions are not possible
- Converting RGB to CMYK will often dull brighter colors
- Blacks can appear duller in CMYK compared to RGB
- CMYK has limited capability to match highly saturated RGB colors
- Most color management systems use color profiling between devices to improve conversions
- There can be loss of color accuracy when converting between the two models
Professional designers use high quality color management tools to get the closest match between RGB and CMYK. But some colors will change when moving designs between digital and print formats.
Uses of RGB and CMYK Color Models
Here are some of the common uses of RGB and CMYK color models:
RGB Color Uses
- Computer monitors
- Televisions and display screens
- Digital cameras
- Image scanners
- Smartphone displays
- LED and LCD screens
- Video projectors
- Digital signage
- Web graphics
- Digital illustrations
- Computer graphics
- Video games
- Multimedia applications
CMYK Color Uses
- Printed books, magazines, brochures
- Newspapers
- Packaging designs
- Posters
- Signage
- Merchandise
- Fabric printing
- Stickers and labels
- Letters and stationery
- T-shirt printing
- Offset and digital printing
RGB is used wherever colors are displayed digitally using light. This includes computer screens, televisions, projectors and other electronic visual media.
CMYK is predominantly used where color reproduction is needed for physical print materials. The four process colors allow for recreating a wide color gamut for printing presses and printed graphics.
Conclusion
RGB and CMYK provide two different methods for defining and reproducing colors. RGB is an additive color model that uses light to display colors on digital screens. CMYK uses subtractive color by absorbing and reflecting select wavelengths for printing color.
Key differences include:
- RGB uses light while CMYK uses pigment
- RGB has a wider gamut and more vibrant colors
- CMYK has a more limited color range
- RGB defines colors using numerical values
- CMYK uses percentage values
Understanding these differences allows designers to create graphics, images and documents that will have accurate color reproduction across digital and print formats.
While both models have their strengths, RGB’s wider range makes it great for digital media and displays. CMYK works very well for commercial printing purposes even though it has a reduced color gamut compared to RGB.
By learning how to properly convert between RGB and CMYK, both striking on-screen graphics and beautifully printed materials can be produced.
