How can I prevent color blindness?

You cannot. Color deficiency is an inherited condition in which the colored light receptors have a spectral shift or are completely lacking in one type of color receptor. The receptor count is usually normal so acuity is not affected. This occurs more often in males. There are no known fixes.
Can't prevent it. Color blindness is a genetic disorder. That is to say, if someone is going to develop color blindness there is nothing that will prevent it because the occurrence of this condition is due to the chromosomes inherited at birth.

Related Questions

Can my color blindness prevent me from getting a bank clerical job?

May be. Color vision is important for occupations using telephone or computer networking cabling, as the individual wires inside the cables are color-coded using green, orange, brown, blue and white colors. Electronic wiring, transformers, resistors, and capacitors are color-coded as well, using black, brown, red, orange, green, yellow, blue, violet, gray, white, silver, gold. Read more...