What does it mean a trait is said to be sex-linked?
Generally the trait is on the X chromosome, as the Y is rather small and full of deleterious mutations and has few working genes. But and trait that is located on a sex chromosome is said to be sex linked. Naturally, women have two, XX, chromosomes, so ore protected statistically from many sex linked recessive disorders.
Yes. Because the colorblind trait is a sexlinked trait and is found in the X chromosome that is inherited from the mother, men that only have one X chromosome will develop colorblindness if the trait is found in this gene. For a woman to get it, she would need to have the colorblind gene on both x chromosomes. Therefore the girl´s dad would have to be colorblind and the mother at least a carrier.