Picking up where I have left, I have a nice addition to my collection of colour tools for visualisation experts: http://color.hailpixel.com
What you see below is the whole interface, when you open the website by Devin Hunt.
Choosing colours is easy as pie: Move your mouse pointer around and the area changes its colour. Once you like what you see, click, and the colour will be saved to a part in the browser window, together with its hex code. In the remaining area you can continue to create new colours until you’re satisfied with your palette. Colours can also be selectively deleted again and the URL of the page keeps track of your palette and allows for easy sharing (and, if you will, “export” of the colour values).
These are too many words, best enjoy the simplicity of http://color.hailpixel.com yourself! (Also, visit that frontpage and pull on the thread!)
When designing a map or a visualisation, sooner or later there is the point where you have to choose a range of colours (except in very specific circumstances which may require you to produce a black-and-white or greyscale visualisation). What is there to consider in such a situation?
Appropriate use of colours
According to Bertin‘s (1918–2010) seminal work, Semiologie Graphique, colour (defined as hue with constant value) as a visual variable is both selective and associative. These mean, respectively, that an object with slightly differing hue can be selected with ease out of a group of objects and that objects with identical colour but differing values for other visual variables (e.g., in the case of shape as the other variable: a red circle, a red square and a red triangle) can easily be grouped mentally. Continue reading