CMYK vs RGB: Why Does it Matter?

Do you lose sleep at night wondering why your stickers look darker in real life than the super-rad design on your computer screen? Fear not! We're here to shine some light on the difference between CMYK and RGB colour modes (and why you should always design stickers in CMYK).

10 Sept 2025

TL;DR: If you want your stickers to be true to your vision, design in CMYK colour mode.

Here’s the deal. Printers use CMYK inks, and computer screens show colours in RGB, a digital light-based format.

If you design in RGB colour mode, those bright electric tones you love on screen can turn flat or muted once printed. That’s why switching to CMYK before you even start designing is key to ensuring the stickers are true to your design.

Two circular RGB and CMYK color wheels side by side, each displaying a gradient spectrum of colors from red to blue to green, with varying brightness.

Colour wheel of RGB (left) vs CMYK (right).

Hand holding a sticker with four stylized, colorful abstract shapes labeled "C," "M," "Y," and "K" on a black background.

Highly educational CMYK glitter sticker from @vladislovinit

1. Different Light Sources = Different Colour Experiences

RGB (Red, Green, Blue) is the colour mode your digital screens use. It’s additive, meaning colours are created by mixing light. The more light you add, the brighter the result. Mix all three at full intensity and you get pure white.

CMYK (Cyan, Magenta, Yellow, Key/Black) is the colour mode printers use. It’s subtractive, meaning it works by absorbing light. The more ink, the darker the colour becomes. Mix all four at 100% and you’ll get deep black (or a rich dark brown if your printer's being moody).

In short:

RGB = light emitted from a screen → looks brighter and more vibrant.
CMYK = ink printed on paper/vinyl → looks darker and more muted.

RGB and CMYK color models: RGB shows overlapping red, green, blue circles; CMYK shows cyan, magenta, yellow, black circles.

2. RGB Can Display More Colours Than CMYK

RGB has a wider colour gamut (aka range of colours it can display) than CMYK.

Colours that look amazing on screen, like neon turquoise or vivid pinks, can’t be replicated in CMYK colour mode, which means the printer has to interpret the colour itself, choosing the closest one.

The result? They end up looking duller or darker in print.

Think of it like this:

RGB is the wild, neon-loving cousin that can show off super bright electric blues, hot pinks, and glowing greens.
CMYK is the more grounded sibling that deals with real-world limitations, like how ink soaks into material, how colours blend on paper, and how light interacts with physical surfaces.

Diagram showing color gamut comparison: the human eye's spectrum, RGB, and CMYK, with overlapping areas in a triangular shape.

3. Your Screen is Backlit, Real Life (and Stickers) Are Not

Digital screens literally glow. The colours you see on your phone or laptop have light shining through them, which makes everything feel punchier and more vibrant.

But when you print something, we don't know... A sticker, you're now looking at reflected light. The ink absorbs some of that light, so colours naturally appear less luminous and a bit heavier or darker.

Imagine designing a bright yellow sun on your screen… then seeing it print out looking more like a golden egg yolk. That’s the CMYK shift in action.

4. Black Is a Topic in Itself

Just like a sweet reference to Ozzy Osbourne, RGB black is pure darkness. If you remember: RGB is additive, and its black is represented by the absence of red, green, and blue light. With no light, there can be no colour.

CMYK, on the other hand, is subtractive: the more ink, the darker the colour. CMYK black "only" consists of one colour (100% K), which in real life looks more like a darker shade of grey, depending on the printer.

So, to achieve what professional printers often define as “rich black”, C, M, Y values have to be added to the 100% K to get a velvety, deep black look.

Four black color swatch cards with CMYK codes, fanned out on a white background.

Here's How to Design like a Pro.

CMYK isn’t "worse" than RGB, it’s just made for a different medium. But because CMYK can’t reproduce every RGB colour, especially those punchy, screen-bright tones, your sticker may come out darker or less vibrant if you design in RGB.

Design in CMYK from the start if you’re making something for print. That way, what you see is much closer to what you’ll get.
If you start in RGB, convert to CMYK before sending to print. Expect some colour shifts, especially in neons, bright blues, and hot pinks.
Use proofing tools or soft proofing in design software (like Adobe Illustrator or Photoshop) to simulate how colours will appear in print.
Avoid super bright digital-only colours if you want a smooth print translation.