The best example I can think of is my photography portfolio (which is no longer online, instead visit Tim Trott on Flickr). On my original portfolio, I created a brown/gold/grey palette. I was quite pleased with it until a friend commented that blue and green didn't go together, to which I replied: "there is no blue...".
Since my colour palette didn't go down too well I had a look on the web and found a colour-blindness filter which reads in a website and produces a filtered version based on various colour blindness defects. Apparently, I have an anomalous form of protan, commonly called red-green colour-blind.
When I showed my friends the filtered version - the version where I could see no difference between the real version and the filtered version - and they could see what I saw, they then all said that my choice of colours was good after all. It's just that I saw the colours wrong.
The two screen shots below show my first version (left) and how I see the colours (right).
I cannot see any difference between the two, but apparently, the links on the left-hand side are blue, not grey and the logo and heading are bright green, not gold.
Although there are good guidelines on developing websites and how to design web accessible pages for the colour-blind as well as tools for evaluating how colour-blind people will see various web design graphics, there does not seem to be any resources for colour-blind web designers who need a filter to see how the palette looks to a normal person.
This is a great shame, as I could really do without this handicap especially seeing as I have enough trouble with a lack of colour creativity in the first place!
The Ishihara test for colour-blindness shows a random pattern of dots and depending on colour-blindness you will either see a number, a pattern or nothing.
If you have any colour blind resources that could be of help, please let me know and I'll gladly put up some links.https://www.flickr.com/photos/timtrott/