Where I grew up there was a clear distinction between a deficiency and total blindness, this is also distinguished by the standard tests. (And definitely not for political correctness - that had a completely different meaning )
No, that is not correct.
I was more expressing how I value such a black&white question.
I am quite color-blind, about as bad as you can be without seeing just pure black and white. Without contextual clues (like the order of the stoplight, jeans are usually blue, etc.) I have a really hard time distinguishing these color combination:
Red-green (really common in men)
Yellow-green (a real problem with LEDs in electronics that I work on)
And any kind if "subtle" (mauve, salmon, taupe, etc.) or non-primary color is kind of lost to me.
This is caused by missing "cones" in my eyes, an inherited condition.
"Color blindness (color vision deficiency) is a condition in which certain colors cannot be distinguished, and is most commonly due to an inherited condition. Red/Green color blindness is by far the most common form, about 99%, and causes problems in distinguishing reds and greens."
But, my point is, as software engineers, it's really important NOT to put such a huge percent of users needlessly in a difficult position. For example, never use color as the primary indicator of state; combine color with an icon or text. Use "color blind safe" pallets. There are examples of these on the Internet. If you go out of your way to have a color-blind-friendly product, chances are it will also be better for normal users.
PS. I've never had a problem seeing a traffic light, although I did once try on a pair of purple jeans in a store!