deuteranomalous

For example, in the evening, dark green cars appear to be black to Deuteranomalous people.

The deuteranomalous person is considered "green weak".

From a practical standpoint though, many protanomalous and deuteranomalous people have very little difficulty carrying out tasks that require normal color vision.

One very important difference between deuteranomalous individuals and protanomalous individuals is deuteranomalous individuals do not have the loss of "brightness" problem.

In order to match a given spectral yellow light, protanomalous observers need more red light in a red/green mixture than a normal observer, and deuteranomalous observers need more green.

If this is done in front of a large audience of males, as the proportion of red is increased from a low value, first a small proportion of the audience will declare a match, while most will see the mixed light as greenish; these are the deuteranomalous observers.