This is not true. That women cannot have the congenital dichromacy (or anomalous trichromacy) that biological males commonly have is flat out wrong. A biological female can still be a protan or deutan, but the phenotype requires that both X chromosomes carry the recessive color vision-deficient alleles. Nevertheless, given that ~8% of all X chromosomes have such a gene regardless of sex, the incidence in the female population is still around half a percent, which is not insignificant.

Interestingly, one form of tetrachromacy in females actually has the same cause as color vision deficiency in some males (specifically anomalous trichromacy). From what I understand, only one X chromosome is active per cone cell, and which one is active is random. So, half of such a person’s cone cells of one type are “normal” while the rest of that type are anomalous and have a slightly different peak wavelength. The net result is four different types of cone cells, i.e., tetrachromacy, which may have an incidence of more than 10% in females.