Colour Blindness Simulator

See roughly how a colour looks to someone who is colour blind.

Free
No signup
Nothing uploaded
No watermark

Colour

Protanopia — red-blind (about 1% of men)

#2563EB looks like #4040CA

Deuteranopia — green-blind (about 1% of men)

#2563EB looks like #3C38C2

Tritanopia — blue-blind (very rare)

#2563EB looks like #28B0AA

Achromatopsia — no colour at all (extremely rare)

#2563EB looks like #606060

Roughly what each colour looks like — these are the standard simulation matrices, which approximate a perceptual experience rather than measure one. The practical lesson holds either way: never let colour be the only thing carrying meaning.

Worked out in your browser. Nothing you enter or open is uploaded.

How to Use the Colour Blindness Simulator Online

Shows roughly how a colour looks to someone who is colour blind. Around 8% of men have some form of it, deuteranomaly being the most common — which is why red and green must never be the only thing distinguishing two states in an interface.

No software to install Free Works on any device

Step-by-Step Guide to Using the Colour Blindness Simulator

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1. Fill in the fields with your own numbers
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2. The answer updates as you type — there is no button to press
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3. Read the breakdown underneath to see how the figure was reached

Try it now

What is the Colour Blindness Simulator?

Why Use Colour and CSS Tools?

Choosing colours that work together and writing CSS for shadows, gradients or grids takes a lot of trial and error. These tools show a live preview as you adjust, then hand you the colour codes or CSS to copy.

“See it first, then copy the code.”

Live previews while you adjust
Codes in HEX, RGB and HSL
CSS ready to paste
Designs checked for colour blindness

Palettes that work together
Readable text checked for contrast
Print colours in CMYK
Colours taken from photos

Popular Uses for Colour Pickers and CSS Generators

Designers and site owners use these for the same handful of jobs.

Brand colours Build a palette around a logo colour with matching tints, shades and accents.
Readable buttons Check that text on a coloured button passes the WCAG contrast ratio.
Card shadows Adjust a box shadow until a card looks right, then copy the CSS.
Page layouts Set up a CSS grid or flexbox layout visually instead of guessing values.
Print artwork Convert screen colours to CMYK and check bleed before sending a flyer to print.
Colours from a photo Pull the main colours out of a product photo to match a web page.
Colour blind checks See how a chart or poster looks to people with different kinds of colour blindness.
Button styles Design a gradient, glass or soft 3D style button and take the code.

What You Can Do with the Colour Blindness Simulator

Exact where the spaces allow it, and says so where they do not

Contrast is reported against the WCAG thresholds, with the pass or fail stated plainly

Colour-blind simulation uses published transforms rather than an approximate filter

Why Use ToolXkit for Colour Blindness Simulator?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

Design Tools for Different Users

Designers

Build palettes, test contrast and convert colours between HEX, RGB, HSL and CMYK.

Front-end developers

Generate CSS for gradients, shadows, animations and layouts and check it in a preview.

Design students

Learn how colour harmony and CSS properties work by changing them live.

Small business owners

Pick consistent brand colours for a shop sign, website and social posts.

Print designers

Convert colours for print and work out bleed, trim and pixel sizes.

Accessibility testers

Check contrast ratios and preview designs through different types of colour blindness.

Best Times to Pick Colours and Write CSS

These tools help when you are:

Starting a new brand or logo
Fixing text that is hard to read
Styling a button or card
Preparing a flyer for print
Matching a colour from a photo
Laying out a page with grid
Checking a chart for colour blindness
Converting a HEX code to RGB

Frequently Asked Questions

Answers to common questions about this tool.

Do I need to install anything to use the Colour Blindness Simulator?

No. Colour Blindness Simulator runs entirely in your browser — there is nothing to download, no extension and no desktop program. It works the same on Windows, macOS, Linux, Android and iPhone.

Is it safe to use the Colour Blindness Simulator online?

Safer than the usual alternative, yes. Most online tools upload your file to a server you know nothing about, where it sits until someone deletes it. Here the file never leaves your device — the processing happens in the page itself, so there is no server copy to leak, retain or sell.

Can I copy the CSS straight into my project?

Yes. The generators give plain CSS that works in current browsers. Copy it into your stylesheet, then adjust class names or values to fit the rest of your design.

Is Colour Blindness Simulator free for commercial work?

Yes. The colours, palettes and CSS you make are yours to use in client projects, products or anything else, with no credit required and no fee.

Why do my screen colours look different when printed?

Screens mix light in RGB, while printers mix ink in CMYK, and some bright screen colours cannot be printed. Convert to CMYK and ask your printer for a proof before a large print run.

What contrast ratio should my text have?

WCAG asks for at least 4.5 to 1 for normal text and 3 to 1 for large text. The Colour Contrast Checker shows whether your pair passes, so you can adjust before publishing.

Do I need to sign in to use Colour Blindness Simulator?

No. There is no account to create. Open the page, adjust the settings and copy the result. Your choices are worked out on your own device and never leave it.

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