Is there a way to show the version of a document as seen by a colour blind reader?

Question

I’m creating a number of coloured grids with TikZ, which look something like this:

This exercise is designed to demonstrate reflections and rotational symmetry. It’s important that the individual colours be distinguishable, and a problem in the past has been colour blindness. Readers who are colour blind can’t distinguish the individual colours, which makes it harder to see the symmetries.

I’m using the tool Colour Oracle to test the colours against deuteranopia (green deficiency), protanopia (red deficiency) and tritanopia (blue deficiency), but I’d like to be able to output a PDF that retains these filters, without recalculating every colour by hand.

Is there a package that I can use at compile time, or a PDF tool that allows me to simulate colour blindness?

As a bonus, the ability to simulate the desaturation that comes from using a projector in a lit room would also be useful.

(If anybody is interested in the exercise the original version is a problem on the NRICH website. I’m updating it as part of my summer work.)

Answer 1

You could import the file into Adobe Illustrator or PhotoShop (CS4 or later) and use the ``Color Blindness Filters'' which Adobe has implemented:

http://www.adobe.com/accessibility/products/illustrator.edu.html

Blog post on it here: http://blogs.adobe.com/jnack/2008/12/supporting_colorblind_accesibility_in_cs4.html

If it's just flat areas of text or color, you could export to .html and view it here: http://colorfilter.wickline.org/

Answer 2

Not tested, but far less costly as WillAdams' answer, The Gimp seems to have such a capacity through this plugin (and is able to open a PDF as a picture)