RGB is used for screens, while CMYK is for print. 1. RGB (Red, Green, Blue) is an additive model for light-emitting devices. 2. CMYK (Cyan, Magenta, Yellow, Key/Black) is a subtractive model for printing. 3. Using the wrong mode can cause color shifts, so start in CMYK for print and RGB for digital. 4. Change modes via Image > Mode in Photoshop, but be cautious of color changes after editing. 5. Preview CMYK colors with Proof Setup before converting. 6. Use RGB for digital media and CMYK for printed materials, though confirm printer preferences. 7. Save an RGB version if repurposing designs later.

If you've ever worked on a design in Photoshop and prepared it for print, you’ve probably run into the terms RGB and CMYK. These are color modes, and they matter a lot depending on what you're designing for. In short: RGB is for screens, like monitors and phones, while CMYK is for printed materials like brochures or posters. Using the wrong one can lead to unexpected color shifts — like a vibrant blue looking dull when printed.

Let’s break this down a bit more so you know when to use each and how to switch between them in Photoshop.

Why RGB and CMYK Exist

These two color models exist because of how color is created in different mediums.

• RGB (Red, Green, Blue) is an additive color model used by light-emitting devices. When red, green, and blue light combine at full intensity, they create white. This is how your monitor, phone screen, or TV works.

  

• CMYK (Cyan, Magenta, Yellow, Key/Black) is a subtractive color model used in printing. Instead of emitting light, ink absorbs certain wavelengths and reflects others. Combining all colors ideally creates black, though in practice it often looks muddy, which is why black (the "K") is added.

Because of these fundamental differences, colors that look vivid on screen in RGB might not be reproducible accurately in print using CMYK.

How to Switch Between RGB and CMYK in Photoshop

If you're working on a project that may end up in print, it's best to start in CMYK. But if you’re designing for the web or video, stick with RGB.

Here’s how to change the color mode:

1. Open your document in Photoshop.
2. Go to Image > Mode.
3. Choose either RGB Color or CMYK Color from the dropdown.

?? A quick note: switching after heavy editing can cause color shifts. If you’re going from RGB to CMYK, it’s a good idea to check how the colors look and adjust accordingly.

You can also set your default color mode in Edit > Color Settings before starting a new file.

What Happens When Colors Don’t Translate Well

Some colors in RGB simply don’t exist in the CMYK range — especially bright neons or deep blues. When you convert from RGB to CMYK, Photoshop will try to find the closest match, but the result might look duller or less vibrant.

To preview how your image will look in CMYK without converting right away:

• Use View > Proof Setup > Working CMYK.
• Then toggle View > Proof Colors on and off.

This helps you see potential color shifts before committing to the conversion. You can then tweak hues or saturation to compensate.

When to Use Which One

The rule of thumb is simple:

• Use RGB for anything that will be seen on a screen — websites, social media, digital ads, videos.
• Use CMYK for anything that will be printed — business cards, flyers, banners, magazines.

One exception: if you're handing off files to a printer, always confirm their preferred settings. Some print workflows prefer RGB files with specific profiles, especially for high-end work.

Also, keep in mind that saving a file in CMYK limits your editing flexibility later. If you think you might repurpose the design for both print and screen, consider keeping an RGB version as well.

That’s the core difference between RGB and CMYK in Photoshop. It’s not complicated, but it’s easy to overlook — until you get a print proof back and wonder where all the vibrancy went.

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