Opsino

Recognize colors.
Put a name to them.

Opsino helps you name everyday colors if you have color blindness, using your iPhone camera or a photo. Read the color name or hear it with VoiceOver.

Download on the App Store
How Opsino worksExplore features

For iPhone · Free live color identification · No account

Opsino identifies red inside the circle on a red flower.

Find a color name in a few simple steps.

Choose an area in the camera view or a photo, and hear the result with VoiceOver.

Identify colors

Point, measure and read a color name. From red and green to brown, light pink and different shades of gray.

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Colors in photos

Choose a photo and tap an area. Zoom and adjust the circle to explore smaller details.

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Resistor mode

Check color bands in a photo, read the nominal value and tolerance, and save the result locally.

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Adjustable measurement circle

Adjust the measurement area for small details or larger surfaces. Tap once to start a reading.

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Lighting & calibration

Measure with automatic settings, adjust the flashlight and use optional neutral calibration.

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Clear measurement guidance

Low light, movement or several colors? Opsino explains what is making the reading harder.

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VoiceOver & accessibility

Hear results with VoiceOver. Understand text and symbols without having to distinguish red from green.

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Private & offline

Analyze camera frames and selected photos on your iPhone. No account or upload for analysis.

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iPhone Duo

Live color identification outside, a larger photo view inside.

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From camera image to color name.

There is no photo to take or upload. Opsino analyzes current camera frames directly on your iPhone.

  1. Aim

    Choose a plain, matte patch where possible. Swipe on the circle to fit it to the area.

  2. Measure

    Tap the circle or Measure. Hold your iPhone still for a moment while the camera adjusts.

  3. Read the color and guidance

    Opsino displays the last reading. When needed, guidance suggests how to improve the light or measurement area.

More about color identification →
Opsino’s camera guide explains measuring, the circle, flashlight, photos and optional neutral calibration.
The essential controls are also explained inside the app.

New: colors in photos

Your photo can give you a color name, too.

Choose a photo and tap the area you want to identify. Opsino shows the main color and, when identifiable, a finer shade. Zoom and adjust the measurement circle to explore small details. Your original stays unchanged.

  1. Choose a photo

    Open the iOS photo picker with the photo icon. Opsino receives only the image you choose.

  2. Tap an area

    A tap places the circle. Adjust its size or use two fingers to zoom in on a detail.

  3. Understand the image color

    Read the color name and guidance. The result describes the color in the photo; lighting and filters used in the picture can change it.

Explore photo mode →
Opsino analyzes a tulip photo: the circle is on a petal and the result reads red.
A selected area in the photo gets a color name.

Main color first. Finer shade below.

In camera and photo modes, Opsino first shows a familiar main color such as red, green, blue or pink. When a more specific shade can be identified, it appears below – for example, mint green under green or magenta under red. Guidance helps you interpret uncertain results.

Opsino identifies green on a pale guitar finish.
Green as the color category for the pale guitar finish.

Easier to read with less transparency

Use the iOS settings Increase Contrast and Reduce Transparency to adapt the display to your needs. Result cards stand out more clearly from the camera view or photo.

Find these options in Settings → Accessibility → Display & Text Size.

Opsino shows red as the main color and magenta as the finer shade with Increase Contrast and Reduce Transparency enabled.
Photo mode with increased contrast and reduced transparency.

Resistor mode

Read resistor color codes from photos.

What do the colored bands on a resistor mean? Opsino helps you read the color code in a photo and work out its nominal value.

  1. Take or choose a photo

    Open resistor mode with the Ω button. When Opsino detects a resistor, the view aligns it horizontally. Your original photo stays unchanged.

  2. Check the bands and reading direction

    Numbered lines point to the color bands. Check the suggested colors and reading direction. You can correct colors, move markers and add missing bands.

  3. Read the value and save it locally

    Opsino calculates nominal value and tolerance for four, five or six bands. Six-band codes also include the temperature coefficient. Save the result with its photo and an optional note directly on your iPhone.

The color code describes the nominal value. The app does not measure the actual electrical resistance.

More about resistor mode →
Opsino displays a horizontally aligned resistor with four ordered band markers and the reviewed value 1.1 kΩ ±5%.
Brown, brown, red, gold: 1.1 kΩ ±5%. The band sequence was reviewed and saved in the app.

Light changes how colors appear.

Warm lighting, a reflection or several colors in the circle can affect the result. Opsino describes detected limitations with text and symbols. Neutral calibration against a matte gray or white surface can help account for the current lighting.

Understand lighting & calibration →

The idea behind Opsino

For my brother. And others who experience colors differently.

My brother has red-green color blindness. That was the starting point for Opsino: an app to help him identify colors in everyday life. The idea is to turn a color into a word he can read or hear with VoiceOver.

I want Opsino to offer a small, practical tool that is close at hand whenever a color is difficult to identify.

Why the name Opsino?

The name comes from “opsin”. Opsins are proteins in the light-sensing cells of the retina and form part of its light-sensitive pigments. Different opsins in cone cells allow them to respond to different wavelengths of light, providing a basis for color vision.

More about opsins and color vision · MedlinePlus

Identify colors without sharing images.

Camera frames and selected photos are analyzed on your iPhone. Opsino needs no account or image upload for this. You control camera access and photo selection.

More about privacy & offline use →

Frequently asked questions

What is Opsino?

Opsino is a color identification app for iPhone. It names the estimated color in a selected camera area or photo and explains possible limitations.

Do I need an internet connection?

Color identification works offline. Photos need to be saved on your iPhone.

Can I hear color names instead of reading them?

Yes. With VoiceOver enabled, Opsino announces the color name and related measurement guidance.

How accurate is a color reading?

The color name is an estimate. Lighting, reflections and the selected surface affect the result. Even daylight, a matte surface and holding your iPhone steady help; Opsino does not replace professional color measurement.

Opsino for your iPhone

Free with optional in-app purchases for Photo Mode and Resistor Mode.

Download on the App Store