Explanation

Colour blindness is caused by recessive sex-linked gene carried by X-chromosome. So, in male, one recessive gene is sufficient for its expression, i.e., $\left( X^{C}Y \right)$ but female needs two recessive gene$\left( X^{C}X^{C} \right)$ for the expression of colour blindness. Mother will colourblind with A blood group and father normal with blood group-B as$-$ So, all the sons will be colourblind with AB blood group. [image:5d_image35.jpeg]