Try to explain with your words what is osmosis.

Passage of a solvent (such as water) from a lower-concentration solution to a higher-concentration solution

explanation:

Passage of a solvent (such as water) from a lower-concentration solution to a higher-concentration solution, by a semi-permeable layer (that enables the solvent to pass but not what is diffused in it) departing the two extracts. The flow of solvent ends when both solutions become even in concentration. In nature, osmosis is a primary source by means of which nutrients are carried to the cells.

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)