You may be like me - partially color blind. Here are a few web sites that give you free color blind tests.
http://colorvisiontesting.com/online%20test.htm
http://www.toledo-bend.com/colorblind/Ishihara.asp
http://www.colors-4life.com/color-blind-test.html
Looking at the sample test on the second link, I verify that I have 'red/green' color blindness. If I really, really strain to see the numbers in the last two circles, I can sort of see them. But it is very difficult.
Please note that the links give examples of the color blind tests. There are more tests done when you go to an opthamologist for an eye exam AND your color blindness is tested.
My solution is to make quilts with no more than 4 fabrics. It seems to work for me.
By the way, I didn't know I had any color deficiency until I was 20. I applied for a job where good color vision was a requirement, and couldn't pass the color test. I do see color, just not the way other people do.