The english physician ronald ross wanted to try to find the cause of malaria. based on his observations, ross suggested that the anopheles mosquito spread malaria from person to person. this suggestions

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)

this might