A man and a woman both have normal vision, they have two children, a son with normal vision and a daughter ?

A man and a woman both have normal vision, they have two children, a son with normal vision and a daughter which has red green color blindness, a linked (to the X chromosome) recessive gene. The man sues his wife for divorce on grounds of infidelity. If you were the attorny, could you use this evidence in your case? Yes or No. If yes which son provides the evidence of infedility the son or the daughter?