Why does it always say In gamut?

Because a hex colour is an sRGB value by definition, so it cannot fall outside the space being tested. The CMYK figures beside it are where the useful information is.

What does a high single channel mean?

That the colour relies on one ink being almost fully saturated, which is the usual reason a vivid screen colour cannot be matched on paper.

Can I check a wide-gamut colour?

Not here. Only hex values can be entered, so there is no way to test an oklch or P3 colour that falls outside sRGB.

Can a hex colour ever come back out of gamut?

No. A hex value is an sRGB value by definition, so any colour that can be typed into the field is inside the space being tested and the verdict reads In gamut for every valid input. The reading that carries real information is the CMYK approximation beside it.

Color Gamut Checker

Q: Are the CMYK numbers a real separation?

No — they are an arithmetic conversion from the same colour rather than a profile-based separation, so they approximate what a press would produce rather than predicting it.

Color

#3B82F6

Gamut

sRGB

In gamut

CMYK approx

C76 M47 Y0 K4

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The color gamut checker compares a colour against the sRGB space and prints its CMYK approximation, which is the number that decides whether a colour is likely to be printable.

What is Color Gamut Checker?

Pick a colour and the page returns three things: a large swatch, a gamut verdict against sRGB, and an approximation of the same colour in CMYK written as the familiar four figures. The layout puts the swatch on the left and the readings on the right, so the colour and its numbers are visible together.

One property of the tool is worth stating before anything else, because it explains the verdict: a hex value is an sRGB value by definition.
Any colour that can be typed into the field is inside the space being tested, so the gamut line reads In gamut for every valid input and an out-of-gamut warning cannot be produced from a hex code.
The reading that carries real information is the CMYK one beside it.

The CMYK figures are an arithmetic conversion from the same colour rather than a profile-based separation, so they approximate what a print process would produce rather than predicting it. What they are good for is spotting the colours that will not survive conversion: a vivid green or an electric blue typically arrives with one channel near a hundred percent and the others low, which is the shape of a colour that a four-ink process cannot reproduce.

Reading the conversion alongside the swatch is the practical use of the page. A brand colour chosen on screen can look entirely reasonable and then arrive with a CMYK breakdown that no coated stock will match, and seeing both at once makes that explicit before a print run rather than after. For screen-only work the same figures are a useful sanity check that a chosen colour is not sitting at the edge of what any process can show.

What the page does not do is compare two spaces properly. There is no wide-gamut input, no oklch or P3 entry, no render intent and no soft-proof preview, so the honest reading is a screen value with its ink approximation attached rather than a colour-managed comparison.

Reading the conversion beside the swatch is the habit worth forming. The colours most likely to raise a flag in a real print workflow are the ones whose ink figures show a single channel close to full with the others low, and this page makes that pattern visible immediately rather than after a press check. A gamut warning color on screen is still only a warning, though: the figures here are arithmetic rather than profiled, so the practical use is to shortlist candidates and confirm the survivors with a proof instead of treating the reading as final.

Limits: one colour at a time, a verdict that valid inputs always pass, an arithmetic CMYK approximation with no profile, no print standard selection and no export beyond reading the figures.
Within those bounds, as a color gamut checker it answers is my color printable with a cmyk approximation to look at, and as an srgb gamut check it is at least explicit that the answer for any hex colour is yes.

How to use Color Gamut Checker

Pick the colour you want to check.
Read the gamut line and the CMYK approximation on the right.
Judge the ink figures — a channel near full alongside low others is the shape of a colour print cannot hold.

When to use Color Gamut Checker vs related tools

Use this when a screen colour is heading for print and its ink approximation needs a first look. Use the print accuracy checker when the question is whether a colour sits too close to the ends of the range, or a profile-based tool when the conversion has to be accurate. The print accuracy checker is the tool for whether a colour sits too close to the ends of the CMYK range, and the CMYK channel mixer works the ink channels directly.

Privacy & Security

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