How do people contract the disease color blindness?
Color blindness is hereditary and non-communicable.
There is no way to prevent color blindness. There is no way to prevent acquired color blindness, that is associated with Alzheimer's disease, diabetes mellitus, leukemia, liver disease, and much more. Some forms of acquired color blindness may be prevented. Limiting use of alcohol and drugs such as antibiotics, barbiturates, anti-tuberculosis drugs, high blood pressure medications, and several other medications. When avoiding those, you are lowering the chances of becoming color blind.