A property professional with nearly 20 years experience of estate agency in Suffolk and North Essex. During that time I have carried out market appraisals on over 5000 residential properties and have helped over 1500 people successfully sell their home.
Therefore, a son from a color-blind mother (who receives the trait from his mother on the X-chromosome) will always be color-blind, regardless of the state of the father (who can only give his son a Y-chromosome).
He said some patients say they see contrast differently in each eye, but not color. So it seems it's not very common. My dad is color blind (rather severely), my mother has normal color vision, and I'm female, btw.