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Chromacy

Is it blue or green? Settle it.

Chromacy finds the color of the thing in your photo, ignoring the background, names it the way people do, and settles the argument with color science. Everything runs on your iPhone.
How it worksApp Store (coming soon)

See it work

Section titled “See it work”
The result screen: the photo of a turquoise car with a marker on its paint, the colors in the photo, and the question, is it blue or green?
It finds the car, not the grass, and marks the spot it measured.
The verdict: closer to blue, with the color beside what people call blue and green, and the perceptual hue wheel.
The answer, with the colors side by side and the hue wheel that decides it.
What people call the color, and how it looks with each kind of color vision.
The names people use for it, and how it looks to others.
A tennis ball mostly in shade behind a fence, measured on its lit felt: closer to yellow.
A tennis ball mostly in shade reads where it’s lit: closer to yellow, but only just.

Real screenshots and a screen recording of Chromacy on iPhone. Photos: turquoise car by Clem Onojeghuo and tennis ball, both CC0 on Wikimedia Commons.

One color, three measures

Section titled “One color, three measures”

Ask “blue or green?” about a photo and Chromacy doesn’t just pick one. It measures the color against what people call blue and what people call green, in three ways, and tells you how close the call is.

#00C0C0
“Blue or green?”
Closer to green.
How it measures up
Perceptual hue (OKLCh): 52° from green, 69° from bluegreenOverall difference (CIEDE2000): 30.9 to green, 49.8 to bluegreenThe familiar HSV color wheel: 58° from green, 43° from blueblue
How much of each hue it appears to contain (CAM16)

A result from Chromacy’s color code, drawn for this page (not a screenshot of the app). It’s a near-even blend, which is exactly why people argue about colors like this one. The HSV wheel disagrees, because it treats hue differently from how eyes do.

Why Chromacy?

Section titled “Why Chromacy?”

Finds the subject

No need to crop. Chromacy finds the main color of the thing in your photo and ignores the background. Tap anywhere to measure a different spot.

Names it like people do

Names come from a survey in which about 222,500 people named colors on their own screens. “Navy” means what people call navy, from 920 names.

Answers your question

Ask “is it blue or green?” or “is it navy?” in your own words. You get an answer, the reason in plain words, and how close the call is.

Real color science

Perceptual hue in OKLCh, overall difference by CIEDE2000, and CAM16 for how much of each hue a color appears to contain. How it works.

Through other eyes

See the color as it looks with red-green and blue-yellow color vision deficiency, or with no color at all, and what each would call it.

Private by design

Your photos and results stay on your iPhone. No account, no server, no analytics, ads or tracking. Privacy policy.

How it works

Section titled “How it works”
1. Take a photoOr pick one from your library.
2. Subject foundIts main color, with the background set aside.
3. NamedThe names people use for it, and the basic color word.
4. AnsweredYour question, with the reason and how close it is.

Under the hood, Chromacy groups the photo’s pixels by how alike they look, joins the lit and shaded parts of the same thing, and scores each group by how much it looks like the subject rather than the backdrop. How it works explains each step and names the science.

Through other eyes

Section titled “Through other eyes”

The same color looks different to people with different color vision. Here’s #00C0C0 as Chromacy simulates it, with the basic color word each would use:

Typical visiongreen

Red-green (common)blue

Red-green (less common)grey

Blue-yellow (rare)green

No colorgrey

Simulated with the method of Machado, Oliveira and Fernandes (2009).

And more

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  • White balance. Tap something white or grey in the photo, and Chromacy removes the color cast of the light from the measurement.
  • Color harmonies. Complementary, analogous, triadic and split complementary colors that go with the one it found.
  • History. Every result you save stays on your iPhone.
  • Share images. A card with the color and the answer, made on your iPhone and shared wherever you like. Here’s the one for the car:

Pricing

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Free trial

Free 5 photos
  • Almost everything Chromacy does
  • Share images carry a “Chromacy trial” watermark
  • Your saved results stay viewable and shareable afterward

Chromacy Pro

$3.99 once, no subscription
  • Unlimited photos
  • On-device AI analysis (Apple Intelligence iPhones)
  • Live camera color picking
  • iCloud sync across your devices
  • Palette export
  • Clean share images

See pricing for what’s in each.

Download

Section titled “Download”
Download on the App StoreComing soon

For iPhone with iOS 17 or later. Free to try, then $3.99 once for Pro.