Numbers or shapes that seem clear to one person can blend into the background for another. The Color Blind Test includes colour-based visual tasks and accompanying questions. Before starting, take a moment to check your screen and viewing conditions so the images are as easy to see as possible.
The test and basic information are free. This version contains 79 questions. Set aside time to read the items, think about your own experience, and choose the closest available response.
What to notice when colours are hard to tell apart
Colour vision differences can make particular shades harder to distinguish. This does not always mean seeing the world only in black and white. In daily life, the difficulty may be a pair of chart lines that look alike, a colour-coded label, or a number that does not stand out from a dotted background.
This online version contains 79 items in total, including image-based tasks and accompanying questions. A digital display changes how colour is presented: brightness settings, filters, glare, and the display itself can affect what you see. Do not interpret every unclear image as evidence of a colour vision difference.
What this can look like in everyday life
Imagine two series on a chart distinguished only by red and green. If they are hard to separate, a solid line and a dashed line may help you read the same information. This is an accessibility adjustment, not a measure of intelligence or attention.
A light shining on your screen can make a picture difficult to read even when its colours would otherwise be clear. Notice whether changing the viewing angle or removing glare changes what you can see.
How to approach the questions
- Use a comfortably sized screen and view the full image before choosing an option.
- Turn off colour-changing night modes or blue-light filters while viewing the images.
- Avoid strong glare and use a comfortable brightness setting.
- Choose what you actually see rather than trying to work out what the image is supposed to show.
- Read the accompanying questions separately; the whole item count is not a count of colour plates.
Make colour-coded information easier to use
Think of a colour-coded task that is difficult for you, such as reading a calendar, chart, or label. Add a second cue where possible: a written name, pattern, icon, or position. You can also ask someone to label a colour rather than relying on a guess.
If difficulty distinguishing colours is persistent, an optometrist can check colour vision under suitable conditions. A sudden change in vision deserves prompt medical advice rather than repeated online testing.
The NHS explanation of colour vision deficiency describes everyday difficulties and professional testing. It does not establish accuracy for this screen-based version.
Common questions
Can my phone affect what I see?
Yes. Display settings, colour filters, screen size, and glare can change an image's appearance. Check those conditions before comparing experiences.
Why should I avoid guessing?
The useful response is the option closest to what you can see. Working out a likely number from its position can conceal what was actually visible.
What is available after finishing?
The test and basic information are free. If you would like to explore the written interpretation further, an expanded report is available as an optional paid addition.
