So. I have a question. Males are more prone to color blindness because the gene that, when defective, causes color blindness lies on the X Chromosome of which men have only one copy. Therefore, if the man's one X chromosome has that defective gene, then he's fucked. However, here's the issue. Women do have two X chromosomes, but only one of them is active. The other is wrapped up in heterochromatin and tucked away. The inactive X isn't completely inert. There are some genes that are still active, but very few. And, for the most part, these genes are pseudoautosomal genes, meaning that these are genes which are also expressed on the Y chromosome. So, the color blindness gene can't be one of these. Therefore, women basically also have only one X chromosome, just like men. But they are statistically less likely to be color blind? Is there a biological reason for this? Is the color blindness gene expressed on the inactive chromosome? Or is it a statistical reason? I.e. 3/4 of all X/Y genes in population are X because women have two while men have one. Despite the fact that only one is active, does this statistically confer an advantage on women in the color blindness issue? I'm kinda confused here.