Category Archives: Tools

Color Blindness Simulator: New Tool Released on Colblindor

Did you ever wonder how it looks like to be colorblind? It is not easy at all to describe color blindness in words. But it is much easier to show it on an image, if you have the right tool.

Color Blindness Simulator
Color Blindness Simulator

Just today I released a second tool on Colblindor. I call it Coblis, a very effective color blindness simulator.

Coblis is based on Michael’s color matrix from ColorJack. Basically the tool manipulates the colors of an image in such a way, that the result is the same image as seen by a particular type of colorblind people.

Let’s have a look what exactly you can do with the color blindness simulator:

  • Choose from nine different color vision types.
  • All possible color vision deficiencies can be simulated.
  • Try out image manipulation with a sample image…
  • …or upload your own image to change its colors as colorblind people perceive them.

The following gallery should give you a quite good impression of what you can do with the tool. If you start with the image in the center the color blindness simulator will produce the following color blindness views (clockwise): Red-Blind/Protanopia, Green-Blind/Deuteranopia, Blue-Blind/Tritanopia, Red-Weak/Protanomaly, Green-Weak/Deuteranomaly, Blue-Weak/Tritanomaly, Monochromacy/Achromatopsia, and Blue Cone Monochromacy.

Color Blindness Simulator: Example Picture
Color Blindness Simulator: Example Picture (taken by Gaetan Lee)

If you haven’t tried it out yet, this is the time to go and check out Coblis, my color blindness simulator. Comments are very welcome.

Improving Color Vision with Lenses for the Colorblind

Every person suffering from color vision deficiency has the same dream: I would like to see the world as everyone else can and I would like to be able to name colors correctly. Color correcting lenses claim to make this dream come true.

The History of Correcting Color Vision

It is said that already in 1837 a German scientist called Seebeck was writing about the possibility to correct color vision deficiency with some sort of lenses. But only in the twentieth century many people investigated and developed different types of tinted lenses and glasses which should help colorblind people to improve their vision.

Many people thought that you really can correct a color vision deficiency and turn it into normal vision. As of today it is well known, that color blindness is in most cases a genetic defect which can’t be corrected except with not yet existent genetic manipulation.

The System of Lenses Enhancing Color Perception

How does it work? It is actually very simple. You just use a tinted lens in one of your eyes, usually in your non dominant eye, and that’s it. In this case both eyes actually see different colors and because of that the brain can extract some other information out of certain colors. You can also use two different tints in each of your eyes. This depends very much on ones personal impression. But it definitely won’t work if you use the same colored lenses in both eyes.

This works for all types of color blindness (protanopia, deuteranopia, tritanopia) in the whole range of severities, with one exception. If you suffer from a complete color blindness (achromatopsia) there is currently no system which can give you back color vision.

The Things You Should Know about Improving Color Vision

First of all you can’t really improve color vision, you can only let’s say adjust your color sensation. The manufacturers claim that you can pass Ishihara plates tests without any errors when using such lenses. And that might be true. But this doesn’t mean that your overall color perception is enhanced. You will also loose some of your color perception in another area of the color spectrum.

Facts You
Should Know

Here are some of the main handicaps when you are using tinted lenses to improve your color vision:

  • The performance on Ishihara plate tests improves a lot. But in contrary there is no significant improvement in lantern tests and in color arrangement tests.
  • Color perception improves in your problem area like red-green but at the expense of an increase in blue-yellow confusion.
  • Most people experience difficulties in dim light or at night when wearing color correcting lenses.
  • You might experience some distracting effects like lustre, fluorescence, 3-dimensional effects, judgment of distance and motion.

But most important: Don’t wear them for driving! If you come into dim light situations like a tunnel you might have some problems with judgment of distance or motion which isn’t safe for driving.

The Results of a Scientific Study about Color Correcting Lenses

In 2000 a group of four scientists of the University of New South Wales, Sydney, tested the ChromaGen contact lens system trying to find out if they can enhance color perception for colorblind people. Fourteen persons suffering from red-green color blindness were involved to test the efficacy in standard color blindness tests, and to evaluate subjective performance in the “real world” over a 2-week lens-wearing period.

Lens tints are available in seven hues (magenta, pink, violet, yellow, aqua, orange and green), and most tints are available at light, medium and dark densities. Most often the pink lens in its darkest density was felt to enhance color perception at the most. Second ranked was the magenta lens, also in the darkest density.

I already included some of the results of this study in the sections above. To me there are two more results which I would like to pass on to you. This might give you a better feeling, if such color enhancing lenses are something for you or not.

A. Would you
pay the price?

At the end of the two week lens-wearing period the people joining the test were asked whether they would be prepared to pay full cost of the lens, which is around $500 per lens. Only two out of 13 would be willing to meet this cost. One of them was really enthusiastic about them and the other one could use them very well on his job as a casino employee.

B. Would you
wear the lens?

One of the persons even returned the lenses, it was too much bother for him. The others expressed interest in wearing them on an occasional basis, maybe once or twice a week. For some of persons the disadvantages of lens wear just outweighed the benefits of them.

The Vendors of Color Correction Lenses

I suppose there are many different vendors all around the world. The following three are the most established ones:

  • ColorMax from Dr. Thomas Azman who developed the ColorCorrection System, a unique system of tests and filters for a systematic approach to color vision correction. (Based in Maryland, USA)
  • ColorView spectacle lenses help people with congenital red-green color deficiency to distinguish colors easier and reduce color confusion. (California, USA)
  • ChromaGen is a unique product that was developed to help patients who suffer from color deficiency. This product was used in the scientific study cited above. (United Kingdom)
  • Colorlite is also a leader in color vision diagnostic and correction. (Hungary)

Some products are available at certain optometrists all around the world.

Unfortunately I think that the dream of seeing colors as a colorblind person doesn’t come true. At least not with products like lenses which enhance color vision. They can get you a better color perception but I think the handicaps outweighed the benefits.

The New York Times also wrote an article about lenses which can enhance color vision at A New Technology That Colors the World (Sort of).

How Many Colors Can You Name in Five Minutes?

I suppose I could have done much better in this quiz, if I would have checked my own tool Color Name & Hue before I tried my best.

And I guarantee you, if you remember just a bunch of the 1640 different color names which are listed in Color Name & Hue, you’ll perform much better than me.

I just tried the How Many Countries Can You Name in Five Minutes and did much better. In the end they counted 43—and 227 remaining…

Color Blindness Tools —
Color Name & Hue

I’m proud to announce my first color blindness tool. Up to now Colblindor was a growing resource of information about color blindness. With this step I would like to go further and start offering tools related to color blindness.

Those tools shall aim for the following two goals:

  1. Help colorblind people to accomplish certain tasks.
  2. Achieve a better understanding of color blindness among non colorblind people.
Color Name & Hue
Color Name & Hue

My first tool which I am releasing today is called Color Name & Hue and it will help you to categorize colors into the main hues Red, Orange, Yellow, Green, Blue, Violet, Brown, Black, Grey, and White.

This tool offers you the following possibilities to find a certain color: either you just browse the color space with the sliders or you enter RGB, HSB or Hex values.

Color Name & Hue will find the closest matching named color among a list of 1640 colors. It will also match this color to its corresponding main hue.

By the way, I compiled the list of colors out of different sources which can be found on the web. Unfortunately not everybody agrees about certain hues so it wasn’t an easy task to find the correct hues. If you find any colors which are definitely matched to the wrong hue just let me know.

I hope you like the tool and it would be interesting to learn in which situations you can use it.

Seekey – Colorblinds See Otherwise Invisible Colors

Seekey tool
Seekey Tool

Are you red-green colorblind? Do you have a handy tool in your pocket which helps you in critical situations to tell certain colors apart? If not you might like to learn more about a tool called Seekey, which exactly can do that for you.

Seekey is a little tool consisting of two different light filters: a red and a green filter. Looking through them will change the way you perceive the color of the object you are focusing on. Based on the difference in color perception through the filters and without filter you can guess the correct color.

Let us have a look at a little example: It is always very tough for a red-green colorblind like me to spot the nice orange blossoms in our green garden. Those two colors just look so similar to my eyes. With Seekey this changes. Looking at the blossoms through the red filter, they get lighter while the surrounding green darkens. The green filter changes the effect and lets all the green lighten up compared to darker blossoms.

Seekey Color Key
Seekey Color Key

There are several color keys coming along with Seekey. Through those color keys you will learn how the color perception changes when looking through one of the two filters. The table to the left shows you an example for the colors red, green, orange and brown.

Kenneth Allblom is the inventor of Seekey. He is living in Sweden and distributing the tool either directly through his web page or otherwise it can be bought at opticians and in certain boat equipment stores in Great Britain, France, Sweden, Finland, Germany, New Zealand and Japan.

A study at the Karolinska Institutet in Stockholm Sweden even showed that the Seekey tool will assist red-green color deficient persons to achieve an 86% improvement at the Ishihara test for color blindness.

Seekey is a handy tool which can help every red-green colorblind person. Visit the Seekey homepage directly to get more detailed information about this little helper.

Monitor Simulates Colorblind Vision

There are many tools available, on- and offline, which show you how a web page or image is seen with a color vision deficiency. These software tools are great and should be used by every web developer.

FlexScan S2411W
FlexScan S2411W with Color
Vision Deficiency Simulation Capabilities

Eizo went even one step further and introduced this simulations into some of their LCD monitors as a hardware solution. This gives you a realtime transition, which doesn’t need any CPU time and is working even with fast moving movies.

They introduced two different simulations: One for red-blind persons (protanopia) and the other mode is used to simulate green-blindness (deuteranopia).

Protanopia and Deuteranopia Simulation in Real Time

Simulates two types of red-green color vision deficiency – protanopia and deuteranopia. The FlexScan S2411W does all the color conversion processing in real time – even moving images. With the bundled UniColor Pro software (Windows Vista/XP/2000 and Mac OS X 10.3.9 or later only) – also developed by EIZO – the designer can instantly switch from a normal viewing mode to the Protanopia and Deuteranopia viewing modes.

Up to now the system is implemented in the models FlexScan S2411W, FlexScan L797-U, and ColorEdge CG241W.

It would be nice to see one of those monitors with the color conversion processing in action. Especially a comparison to some good software simulation tools could be very interesting and show if Eizo can really deliver what they promise.

ColorBlindExt – Better Web Accessibility for Colorblind Users

Have you ever wondered, if you can’t see certain things on a website because of your color blindness? This time is over now—at least for colorblind Firefox users.

The Firefox add-on called ColorBlindExt was released just recently and is a great support to discover things which you couldn’t see up to now. The developers describe it as follows:

This extension helps color blinds while browsing the web, by processing images and text on the page according to the type of user’s color blindness. Color Blindness detection test is included for creating awareness among people.

After installation (see further down) as a first step you should take the color blindness test available through the newly added menu called ColorBlindExt. The test is based on Ishihara plates and will tell you, which type of color blindness you are suffering from. It detects protanopia, deuteranopia, tritanopia and even monochromacy, which means you are completely colorblind.

After taking the test the filter will be set according to your results. This can be changed at any time. Also the filter can be completely enabled or disabled however you like.

ColorBlindExt - Filtered Image
ColorBlindExt – Filtered Image

ColorBlindExt lets you choose to filter whole pages. This can be done either automatically or through the context menu, clicking with your right mouse button anywhere on the page and choose Filter page.

On the other side you can only filter images whereas a little window pops-up, showing you the filtered image by itself.

Personally I like the image filtering on demand. Through this option, which is also available on the context menu when clicking on an image, pictures and diagrams can be enhanced according to my type of color deficient vision.

The developers took the image filtering even one step further. Through the settings you even can adjust the level of deficiency and a choose from a noise reduction and sharpening option. This lets you play around and find the settings which fit the best to your personal color vision.

The tool also has some limitations, which don’t really restrict the usage to me when I look at them.

  • Page contents like flash objects, applets, media players can’t be filtered, it is out of scope.
  • Only elements accessed by DOM are processed.

Unfortunately the installation isn’t a single click and run. I tried to summarize all requirements including the links to get the latest software if you are missing some of them. I hope this helps you to get your colorblind webpage filter up and running without a hassle. Be aware that you need administration privileges if you have to install new software like the Java runtime environment.

Installing ColorBlindExt in 5 Steps

  1. Firefox
  2. Java Runtime Environment
  3. Java Advanced Imaging
    • Version: 1.1.3 or higher
    • Check: Start → Settings → Control Panel → Add or Remove Software
    • Download: – JAI for JRE
  4. Firefox User Registration
    • Why: ColorBlindExt is not yet available as a public download. It is accessible through the Firefox Add-ons sandbox, which is only open for registered users.
    • Registration Form: Firefox Add-ons: New User Registration
  5. ColorBlindExt

Hopefully this tool will help you to access some websites more easily than before or to read some colorful and up to now undistinguishable chart lines. And I also hope this tool isn’t used as an excuse for web designers to disregard accessibility, especially concerning color blindness.

Color Reading Cell Phone

Peter Jones, president of Tenebraex, is a really clever business man. He is making the headlines every few month with some new announcements. This time featured at cnet with the article Bringing color to the colorblind.

It was just about one year ago when the company was in the news with their software called eyePilot. This is a little software tool which helps colorblind people to distinguish and name colors on the computer. I reported about it in the Battle against color blindness with eyePilot and the follow-up post on RGB is not HSV.

Then again when school started last summer, they pushed their tool into some news channels and promoted it further. This time they focused at schools. EyePilot could help many children at school time to overcome their handicap of color blindness—at least in some cases.

Last time I heard about the company was November 2006 when I was contacted by Joanna L. Ossinger from the Wall Street Journal. She wrote an article about tools which help colorblind people and asked me for my opinion. Afterwards I had to ask myself if journalists have a work ethic, because after she got the information I never heard again a word and was mentioned by no word.

Color Reading Cell Phone
Color Reading Cell Phone

And here we are again. This time they neither have a new product to announce nor push their old one again. No, this time they just talk loudly about their ideas and are mainly looking for, well, money. Their new idea is a color reading cell phone.

This idea isn’t that new. The Color Luminator is a similar tool which was already developed by some smart students. Ok, it’s not a cell phone. But these days almost anything could be packed into a cell phone, if you only have a enough money.

From a business perspective, they definitely go the right way. I suppose they already made good money and will grow further with their well established tactics.

From a colorblind perspective it looks different. I did put together the following wish list for Tenebraex:

  1. Release eyePilot to the open source community. This way it could evolve to a nice little application which doesn’t just look like a fast hack with a big marketing machine behind it.
  2. Develop some great plugins for eyePilot. Those will enhance the product and make it a real nice helper tool for every colorblind person. With this strategy you could even earn some money.
  3. Then show us, that you really have something more to offer than just some ideas. Maybe you could get some help from the Color Luminator guys.
  4. After all that, approach cell phone companies and tell us, when you’re done.

If you follow this task list we will maybe soon have some great tools available for all among us affected by color blindness. Otherwise it might take some longer.

Simple Color Translation Algorithms

Two weeks ago I wrote an article about Protanope Tools and how you can translate diagrams to make them more readable for colorblind people. This time we have closer look at the algorithms behind the two color translations.

To understand the how and why of the two color translations we first have look at the RGB color system. The acronym RGB encodes the colors Red, Green and Blue and is used on computer system color displays to—well— display colors.

Concerning red-green color blindness the first two channels (Red/Green) are sometimes not of great help. These two channels are encoding the color axis which gives a red-green colorblind person the most problems in distinguishing different shades. Therefore we are looking for a simple way to transform those two channels.

Red-Green Color Blindness Color Translation Algorithms

Original Color Spectrum

  • Red-Green to Blue-Yellow Translation
    Color Spectrum - Blue-Yellow

    • R -> B
    • G -> G
    • G -> R
  • Red-Green to Green-Magenta Translation
    Color Spectrum - Green-Magenta

    • R -> R
    • G -> G
    • R -> B

The two translation formulas are held very simple but not less effective. They have only one major flaw: the blue channel is completely thrown out and in both cases replaced by the red channel. So you lose a third of the information in the image, all the blue information, except that if you are red-green colorblind you gain a lot of information that was previously lost in the red and green channels.

As Peter, the owner of Protanope Tools, puts it:

I say this is a strength because the simplicity makes it easy to understand exactly what’s happening, so if you know you’re going to lose all the blue information at least that won’t take you by surprise.

Thanks Peter for the information about your simple color translation algorithms you shared with us.

Did you make a Color Blindness Check on your Color Scheme?

There are many online tools which help you to choose an appropriate color scheme based on color theory. ColorJack is one of them. But not just anyone when you take color blindness into account. The creator put quite some effort into the tool to help you understand how a colorblind persons will perceive your chosen color scheme.

The most popular part of ColorJack is the Sphere application. Before I describe you all settings in detail and special adjustments concerning color blindness try it out yourself.

Besides all the settings for choosing your spectral colors according to different color theories and the possibility to set the base color spectrum you have the choice to choose between several different color vision deficiencies.

  • Dichromacy: Protanopia, Deuteranopia and Tritanopia.
  • Anomalous Trichromacy: Protanomaly, Deuteranomaly and Tritanomaly.
  • Monochromacy: Rod Monochromacy and Blue Cone Monochromacy.

The naming needs some further explanation because the labels in the Sphere tool are not well chosen. As for dichromacy which describes the circumstance, that a person has one type of color receptors missing, the correct names end with -opia and not as labeled in the tool with -opy.

The wordings Achromatopy and Achromatomaly used in the tool of ColorJack are also wrong. The correct names are either Rod Monochromacy or Achromatopsia for complete color blindness (absence of all color receptors) and on the other side, if you have only blue color receptors this is called Blue Cone Monochromacy.

Nevertheless the ColorJack Sphere application is a great tool to provide you some good information when you want to check your color scheme to work with any type of color blindness. It does not only show how your colors are perceived by somebody with a color vision deficiency but also shows the according color values. This gives you a hint on how color vision is different if you suffer from color blindness.