It is usually inherited due to faulty photopigments that parents pass down to their children. Complete color blindness...ACHROMATOPSIA... is rare. All these folks see is GRAY or BLACK AND WHITE. Most colorblind folks have trouble with reds and greens and orange. Most colorblinds can still distinguish yellow gray beige blue.
The colorblinds are not to be blamed for being born defective. They had nothing to do with it. It was not a choice. We don't get angry at them for what they cannot see. Do we?
