When designing a site I refer to a color blind chart which shows what colors look like to someone with the most common type of color blindness. Unfortunately I find it difficult to comprehend and I wimp out, going with ultra safe color schemes. What I need is to see the site as a color blind person would. I want to build this tool (this and about 1000 other things).

Writing the core isn’t too difficult, it is a simple palette shift. (Well, writing it quick isn’t too hard, writing it properly might take a while). The more difficult part is validating that each type of color blindness is being properly represented by the algorithm. Even then it can only be taken so far as color representation will differ at the end user device level.

The core should be released as an open source project. It can then be applied to other cool uses like creating a filter in a camera or a camera phone app so you can see the real world in color blind mode in real time.

I personally just want a Greasemonkey script or a browser plugin that will shift the CSS and image colors on screen. Not to say that this will be easy; there will likely be complications with semi-transparent layers, the interactions with inherited styles, and issues with non-raster images like SVG files.

There is a firefox plugin that does the opposite; It changes the palette of images and text based on your particular color blindness. It is GPL so it might serve as a starting point.