What happens when an organism genome (genetic code) is incorrectly copied or changed?

When there is a mistake in the copying of the genetic message that is permanent, a mutation has occurred. Two of the bases in DNA (Cytosine and Thymine) are the most vulnerable, and when this happens, they may pair with each other or themselves and the message is changed.

Explanation:

hope this helps you

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)