Colorblind - what do thay see?

[Gorshi]

I just spent half the day following tangents related to colorblindness; our tech support guy turns out to be colorblind. So it begs the question, what does a colorblind person see?

There is a Mac tool that will transform an area of the screen to show that section as a colorblind person would see it. Most common is red and green both look like yellowish/brownish

you can also look at any website as a colorblind person would see it, hang on checking history....

ok http://colorfilter.wickline.org/?a=1&u= ... me.com;t=m (place any url in the query string)

and

http://michelf.com/projects/sim-daltonism/ (that's the one that works on OS X)

Anyway, colorblindness is pretty common I've found out. And judging from these tools I can say I would hate to be colorblind.