The reason why purple and violet look similar to us is because they stimulate our cones in a similar way, but most other animals don’t share the same types of cones and “post-processing”. This means that to other animals, purple and violet may look completely different!

Now imagine a violet flower petal with a purple pattern on it. Depending on the particular shades, this pattern might be completely invisible to us, while many other animals could see it as clearly as we can see an orange pattern on green background.

It turns out that if all the stars and all the planets in all the galaxies were before you in a terrifying, brilliant, impossible box, the color would you see (while no doubt experiencing a transcendent feeling of oneness) is the most boring color in the world.

How well do you see color? FACT: 1 out of 255 women and 1 out of 12 men have some form of color vision deficiency. Take the online color challenge, based on the Farnsworth Munsell 100 Hue Test.

We extracted the colors from 10 million Creative Commons images on Flickr. Search this collection by color. Addictive and very likely the best color search engine in the world*!

Pick a starting color and get complements, triads, tetrads, etc., calculated automatically.

With the test images on these pages, you can easily adjust the settings of your monitor to get the best possible picture quality. Additionally, there are a number of test images that can help you to judge the image quality of a monitor. You can check the images on this webpage or put them on a usb stick and try them in the computer store like I did when I created these test patterns. These test images are much more revealing regarding monitor shortcomings than ordinary photographs.

Colorifer is a wrapper to run program and colorize it's output. [sic]

According to Wikipedia there are an estimated 10.5 million American men who are red green color blind. I am one of them. I discovered this many years ago and rarely think about it as to me it is normal. However, I have discovered that those around me are endlessly fascinated with it—especially designers. So, to you I provide this public service message on color blindness.