People with color blindness have problems to see red, green or blur or a mix of these colors. And sometimes it is very troublesome for people with color blindness in some certain careers. And usually color blindness are caused by genetic, affected part of the eyes is cones, which are responsible for discerning color. Still some people may develop color blindness in latter life because of trauma or neurological issues.
Well, color blindness is usually caused by a lack of cone cells. Without cone cells, they can only see shades of dark. That is kind of pathetic, I think. However, it may not be permanant so you still have a chance. By the way, if your color blindness is genetic, then you have to admit the sad truth that you will be color blind forever. If it is caused in later time, then you can recover by doing some eye exercise or some useful treatment.